Naming and Understanding Ionic Compounds

Hello, this is a lecture topic video discussing formulas and names of ionic compounds. All right, so let's go back to what an ionic compound is. So generally, when we think about these things, we're thinking about binary ionic compounds. Binary meaning two things, okay? So generally, it's a metal and a nonmetal coming together, okay? This doesn't necessarily have to be the case. Because we talked about in the last lecture topic video, we talked about polyatomic ions, where these groups of covalently bound atoms somewhere in the process of forming these bonds have either lost or they have gained electrons. So we can form these polyatomic cations and these polyatomic anions. Well, these things can also take part. in ionic compounds. And the other thing we want to talk about in this lecture topic video is how do we name hydrates, all right, where we get these metal or these inorganic, I guess is what you would call them, inorganic salts being formed. And sometimes we get these waters that kind of either bond directly to the metal or to the metal complex, but they bind in a very defined ratio. And essentially as these things crystallize, they become part of the crystal. lattice, right? So they become part of the compound. So we want to talk about how do we name those things. But the first thing we want to talk about are how do we name our binary ionic compounds, okay? And so we got two types of these. There's this type one and there's a type two. The type one, all right, is dealing with cations that can only adopt a single charge. So when we're talking about this, these cations are interacting with our non-metal anions. And so what metals are going to actually adopt only a single charge? Well, remember, it's primarily going to be our main group elements, our main group metals. So our group 1A, our 2A. and our 3A metals. Remember, the 1, 2, or 3, if you want a shorthand, right, remember that kind of tells us the types of charges that these metals can adopt. Remember, they're metals, they want to donate their electrons, all right? And by doing so, they move backwards so that they get the electronic configuration of the noble gas that precedes them, and that's stabilizing. So again, our group 1As, what do they want to do? They want to lose one electron. All right. So what you can see is they all form, all right, a single plus charged cation. All right. Our two A's for the same argument form two plus cations, whereas our group three A's form our three plus cations. All right. So when we're talking about our type one binary ionic compounds, these are the metals that we're typically working with. And what are they doing again? They're interacting. with these non-metals. And remember these non-metals, right, they have much higher electron affinities. In other words, they want to accept electrons. It's energetically favorable for them to do so. And by accepting these electrons, what they do is they move forward. So if they adopt the electronic configuration of the noble gas, all right, that follows them. So we get these binary, these type one binary ionic compounds. All right, well, we're naming these things, the cation, all right, it doesn't matter if we're talking about the formula or the name. So the chemical formula or the name, the cation is always listed first, followed by the anion, okay? Cation first, anion second. Now, how do we name our cations? Well, our cations are actually quite easy to name. What we do is we just take the name of the metal and we add ion to the end of it. For example, If we look at lithium, lithium forms a plus one cation. This cation would be called lithium ion, right? Sodium would be sodium ion. Magnesium would be magnesium ion. Aluminum, aluminum ion, so on and so forth. It's actually quite easy to name our monatomic cations, okay? Now, our monatomic... and answer are a little bit different. All right. Cause what we want to do is we want to take the element name. All right. So nitrogen, oxide, fluoride. And what we want to do is drop the ending of that name and add the ending I-D-E. All right. So, for example, we have fluorine. All right. What we want to do, and many times you see this I-N-E ending. OK, what we want to do is we want to drop that. and make it fluoride, okay? So that's I-D-E. And then what do we want to do is we want to add ion to it. So if we have F minus, what would we have? We would have a fluoride ion, okay? So let's look at oxygen. Well, oxygen, okay, it's a little bit different, all right? But we're going to keep the root name. So the OX, it'd be oxygen. And what we would do is drop the YGEN and make it oxide. All right. And then nitrogen would go to nitride. What you can see again is all these guys have this IDE ending. Okay. And then we add ion to the end of it. All right. So that's pretty straightforward for our monatomic. cations. We take the name of that element, whatever that metal is, name it, and then add ion to the end of it. When we're talking about our monatomic anions, we take the root of the name. We drop the ending off of it and add this IDE followed by the word ion. Well, now how do we put them together? Well, what we would do is we just merge the two rules together. So for example, Let's think about LIF, okay? Well, again, we got to start thinking about these formulas. How are we coming up with these formulas, right? One of the driving rules here is that anytime you make a formula, all right, you want that molecule, that compound to carry an overall neutral charge. So they should be neutral in nature. So if lithium, all right, has a plus one. Okay. And fluoride has a minus one. Those two things will come together in a one-to-one ratio to make LIF, which is a neutral compound. Okay. Well, how do we name this? All right. Well, this would be called lithium. It's just the cation name first, fluoride, lithium fluoride. Okay. And so again, merging the two names. The metal is the name of the element followed by ion. The non-metal anion is the root of that non-metal. Drop the ending, put IDE on there and ion. And then when we want to put these things together in a compound, we would call this lithium fluoride. All right. They're no longer ions. So we drop the name ion completely. All right. So let's see here. Can we make up another example? How about merging? Let's merge calcium with oxide. Well, what would our formula be for that? Well, in this case, calcium cation or calcium ion carries a two plus. Okay. Again, these charges are very predictable. Main group element charges are very predictable. We got calcium two plus and we have oxide, which is O2 minus. All right. So again, those charges cancel each other out. All right. And so what they would do is they would come together in a one-to-one ratio. So we could get calcium oxide. And we're dealing with a calcium ion and oxide ion. And so what we would do, we'd name it, again, metal first, followed by the anion. It would be calcium oxide. Now, you'll notice that... I just because I'm just writing quickly. All right. Not really paying attention to this. They're capitalized. I capitalize them. But these names do not need to be capitalized. OK, so calcium. These are not proper nouns is better written like this. And lithium is better written like this. Just so you guys are straight on that. So these are our type 1s. Now, we also have type 2s. Well, the difference here is that when we were talking about our type 1s, these are metals that have defined ionic charges. They carry a defined charge. So our group 1As, again, form these plus 1s. Our group's 2As, 2+, so on and so forth. Well, now what happens when we get to… Our transition metals, okay, our transition metals. Now there's exceptions, all right? There's exceptions like zinc, cadmium, and silver. They're transition metals, but they only carry a defined charge, all right? Zinc is two plus, cadmium is two plus, silver is plus, all right? But one of the defining kind of features, if you will, of these transition metals is that they can adopt. multiple charges okay they can adopt multiple charges and so when we're talking about type two binary ionic compounds that is what we're talking about we're talking about our primarily our transition primarily not always transition metals all right and because our transition metals are bonding with these these um anions all right and we we know because they're transition metals they tend to be able to adopt multiple charges, we have a special way of representing that. We have to represent that by using these parentheses and then the charge listed in Roman numerals. So for example, iron three, okay? Iron three would be written as iron one, two, three. Again, the name of the metal All right. Followed by the the charge on that metal. OK. In Roman numerals, in parentheses, followed by ion. So this would be an iron three ion versus SN4. OK, this would be 10 for ion. OK. And our nonmetals are named just like. what they were before. Our anions are named just as they were before. We take the name of the monatomic nonmetal. We drop the ending of it. So we're going to keep the root of that name. We're going to drop the ending and add the IDE. Okay. And so let's take an example here. All right. What if we have FeCl2 and FeCl2? C L three. Okay. So we have a, a transition metal iron in this case. All right. For both of them followed by our anion, right? What's our anion in this case, it is chloride. All right. So chloride right here. So if we just wrote it like this, there's really nothing that distinguishes the two, although they are very, very different compounds. Okay. And they're very different compounds because that metal is in a different ionic state. All right. So how do we figure out what that ionic state is? Right. So when you're dealing with these compounds that have a transition metal, and again, because the transition metals can adopt multiple different charges. All right. What I would tell you, the rule of thumb that I always tell my students. is let the anion guide you, okay? Let the anion help you figure out what the charge is on that transition metal. So what do I mean by that? Well, again, these non-metals, these non-metal anions, they form very defined charges, right? So nitrogen forms a minus three, and that's because if it adopts or essentially accepts three electrons, it moves over one, two, Three positions on the periodic table. It gets the electronic configuration of the noble gas that follows it. Very stabilizing. All right. So group 5As will want to accept three electrons. Okay. So they'll form three minus anions. 6A. So oxygen and sulfur are two big ones here. All right. They are two away from the noble gas that follows them. So they would like to adopt two electrons. Okay. So they always form. These two minus. anions, all right? And then as we move through 7A, all right, these are our halogens. Our halogens are only a single step away from the noble gas that follows them. So what do they want to do? They want to adopt these minus one charges, all right? So because our anions, in this case, all right, carry very defined charges, we can use that. And knowing the formula, we can use that to determine, all right, what the charge on the metal center is. Okay. So again, if chloride is carrying a minus charge, and if we're talking about FECL2, and there are two of them, right? That means that those chlorides, okay. And that two out front, that's being insinuated because of that two right there, that little subscript two tells you that there are two chlorines or two chlorides bound to a single iron. That's what this kind of nomenclature means here. But if we have two of those and each of them carry a negative charge and our goal, our goal always is to make a neutral compound. That tells you that the iron has to have a two plus charge. So when we're naming this, it would be iron to chloride. Now, again, let's look at iron. iron chloride where there's three chlorides. Okay. Well, again, now we have three chlorides that gives us a total of three minus charge. All right. And we want that one iron to kind of neutralize that. All right. So therefore that iron has to carry a three plus charge. So this would be called or named as iron one, two, three iron, three chloride. Okay. So this is our type two. Okay. Again, type twos are dealing with an anion, a monatomic anion. All right. Very predictable charges. And it is bonding with some cationic species that is coming from a transition metal typically. Okay. And so what you can do again is you can let the anionic charge help you determine what the charge is on that metal center. Okay. And again, I say that this happens a lot, all right, with our transition metals, but they're not the only ones because you can look here, all right, these are main group, so tin and lead, and you can see that both tin and lead are capable of forming more than just a single charge, okay? But typically speaking, anything in the main group, all right, again, typically, not always, there's exceptions to almost any rule you can think of, the typically main group. elements, whether they be metals or non-metals, tend to form very defined charges. Okay, so that's our type one and our type twos. Now, we also said that we have these polyatomic ions, okay? Again, they're all listed here. There's 20, okay? And these things, in the process of forming these molecular bonds, these covalent bonds, all right, they have gained or they have lost an electron somewhere, okay? Again, most of these are polyatomic anions, all right? That's these guys, all right, here. Again, because of the acetate, all right, there's multiple ways people list that, so it's got three boxes, right? But as you can see here, most of these are polyatomic anions. So as these covalent bonds are being formed between these different... atoms, all right, electrons were gained in this case. Okay. So all these guys carry some negative charge. All right. And, but we also have some polyatomic cations as well. So hydronium and ammonium. So that's these guys up here at the top. All right. So we can just circle these here. So we got a couple of polyatomic anions. Now, remember, we want you guys to know these. Okay. So there's, there's 20 here. Um, and I'm going to hopefully in this next slide, take you through some trips that will at least help you with half of them. Okay. That's the goal is for me to give you some tips that'll help you with at least half of them. Well, how do we name things with polyatomic, uh, anions or polyatomic cations? So let's think about sodium, uh, interacting with cyanide. Okay. Um, well, sodium, all right, is a, uh, group one metal. All right. So it's an alkali metal. So it carries an Na plus, right? Carries a single predictable charge, okay? And let's say it's interacting with this polyatomic anion. cyanide. All right. C and minus. Well, again, we want to make this neutral compound. So when we're writing a formula for this compound, all right, we put them in a one-to-one ratio. Okay. And again, we, anytime we have one of something, you don't have to indicate that. All right. So what we would do is we just write sodium cyanide. Okay. Now, how do we name it? Well, it's just like I said, all right, we have, how would we name this? This would be our sodium ion. This would be our cyanide ion. And so when we're putting them together, we would just call this sodium metal first cyanide followed by the anion. All right. So sodium cyanide. Okay. So that's an example using a polyatomic anion. Well, let's look at a polyatomic cation. So this is a really common one that we'll see. All right. It's ammonium. And so let's say that ammonium, again, it's the cation. So it comes first, interacts with chloride. Okay. Or maybe it interacts with another polyatomic anion. All right. Well, how would we name this? Well, again, this is ammonium ion. This is chloride, not chlorine, chloride. We drop the end. We keep the root of the name, drop the end and add IDE. So that'd be chloride ion. And so we would name this ammonium chloride. Okay. How about this next one? Well, again, this is our ammonium ion. And if we look up here, this is another polyatomic. So let's find it in O3. All right. It's right there. Okay. And this is, so this would be called our nitrate ion. And so when we put these things together, It's ammonium nitrate. Okay. We just use the name as it is for the polyatomic, either cation or anion. Okay. So now can I help you with kind of memorizing or learning? I'm not a big fan of that word memorization. All right. Can we learn how to name these guys? Well, some of these is literally brute force. Okay. So which ones do I think are brute force? It's about half of them, okay? Because there's no predictable patterns, all right, that I can kind of tip you off on. All right. So the hydronium, this is one that you'll want to commit to memory. Remember, another way you might see this, all right, instead of H3O+, this is really because there is this H plus interacting with water. That's what gives us our hydronium. And remember this H plus is called a proton. This will become really important here before long. Okay. So you want to remember that one. Cyanide is another one. Oxalate is another one. Permanganate, chromate, dichromate, ammonium, hydroxide, carbonate, and then our acetate. Okay. Again. all three of these acetate representations are perfectly acceptable. Hopefully one of these will click with you more than the others, or maybe you got them all down. Just be prepared to see acetate presented to you in multiple forms. Now, what does that do? That leaves this whole middle, this whole middle swath of compounds, all right, that I can actually provide you with some assistance on how to memorize these things, okay? So these guys, Right here. I can help you with trying to make some sense of these guys. So I kind of cheated. I wrote this stuff out already. All right. And what you see is I line these things up in a very, very particular way. Okay. So what are these things called? All right. These guys that have some element or some nonmetal that's bound to oxygen. Okay. These are called oxy. anions. All right. So there's sulfur and then there's oxygen. Right. And then it's an anion. So that's why it's an oxy. That's the oxygen part. anion coming from that two minus. All right. So each one of these is an oxy anion. And what you find in nature is that some of these guys form what we call oxy anion series. Okay. Meaning that if we're looking over here, all right, we get multiples of these sulfur containing. All right. I've already made a mistake here. Let's just rewrite that. There's multiple of these sulfur compounds that contain different numbers of oxygen, all right? But they are carrying, okay, the same charge, okay? So in this case, this is a sulfur oxyanion series. We have a phosphate containing oxyanion series, a nitrogen containing oxyanion series. And what we want you to know is one of these halogens, all right? So chlorine. But there's oxyanion series for not only chlorine, but there's one for bromine, there's one for iodide, so on and so forth. So as you proceed through chemistry, you will see that there are many more of these oxyanions that we're not expecting you to know right now. But how can we make some sense of these guys? Well, within each of these series here, and there are four, so we got one, two, three, and four. There, there is a, one of these is, is more abundant than the others. Let's just say it that way. Okay. In other words, there was one that was discovered first between, within all of these series. Okay. And what that, what I'd like to call that is the parent is the parent compound. Okay. And because they were found first, typically because they're more abundant, what scientists did, what chemists did was give them the ATE. ending. Okay. So this is a sulfur containing oxyanion series. So this would be called sulfate. So it has the A-T-E ending. Okay. Sulfate. So the one for the phosphorus containing one is the P-O-4-3-minus. That is phosphate. Okay. And then nitrate. And then what do we have? Chlorate. Okay. Again, these are all the ones that are more abundant, more readily known, however you want to think about it. All right. And I call these again, the parent, the parent always gets that A-T-E ending. Okay. So there are 10 different oxy anions listed here. And I will tell you that if you know these four, you know, all 10 of them. Okay. Of course, there's some rules that you kind of need to keep tucked away in the back of your head, but all of this is going to come back. Okay. So this is a good kind of preamble to things that we're going to talk about later. All right. Now what you can see, what distinguishes one of these, the ATE ending from these other guys, it's literally just the number of oxygens. Okay. So you sulfate has four oxygens, still has the same sulfur, still has that two minus charge versus this SO3 two minus, right? So nothing changes except for the number of oxygens. And what you see is that that is true in each one of these series, right? The, the, the kind of the, the root element that makes up the series stays the same. All right. And the overall charge of these anions stay the same. The thing that changes is the number of oxygen. Okay. So if we take what I call the parent compound, all right, or the ATE ending, or ATE containing compound, if we drop one oxygen from that, that is now sulfite. They have the ITE ending. Okay. So if we have phosphate, the only thing that changes from PO4 3 minus to PO3, Three minus is the number of oxygens. We've lost one. So this is now phosphite. Phosphite. We have that I-T-E ending. Then we have nitrate and we have nitrite. And then we have chlorate. And then if we drop one of those oxygens, we have chlorite. All right. So that takes care of eight of the 10. Well, what's going on with this guy? And this guy, right? Well, in one case, if we're looking at the parent, the ATE ending compound, all right, we've gained one oxygen in one and we've lost two oxygens in the other, all right? Well, when we gain one electron, one oxygen, right? We call this now per, we add this prefix per-chlor-8, okay? So everything stays the same except for we add per, okay? The per prefix, right? So now we have per chlorate, chlorate, chlorite, all right? And now what are we going to add? We're going to add, we've lost two oxygens relative to our A-T-E ending. What are we going to do? We're going to add hypo, hypochlorite. We keep the ite ending from the previous guy, the Cl2 minus. All right. That stays the same. And now since we've lost, all right, one oxygen, one additional oxygen, we call it hypochlorite. Okay. So this is what we see in bleach, for example, hypochlorite, sodium hypochlorite. So hypo meaning under or, you know, signifying like less. All right. So that's where the hypo is coming from. So hopefully this little trick here, all right, with a little bit of practice will help you memorize or learn, okay, these 10 oxy anions. And again, this discussion is very pertinent to what we're going to continue to talk about as we proceed through the semester. Okay. So, and again, these rules follow. There are many, many, many, many more oxy anions that are out there. Okay. That are. outside of this table that we've kind of presented to you here. So now let's talk about hydrates. Okay. So what are hydrates? Again, these are when we have these inorganic salts, okay. Everything we've essentially been talking about are inorganic salts. Well, sometimes when these things start to crystallize, what they will do is they will kind of suck up water or soak up water from the environment. And that water becomes an integral part of that. compound. It becomes a part of the compound. Okay. And it's not like it's just randomly soaking up water molecules from the environment. It always happens in a definite ratio or a defined ratio. Okay. And those waters again, either bind to that metal center. All right. Or they bind to that metal complex in general. Okay. So how do we go about naming these things? Well, what we can do is we can name the actual ionic part, just like we've been talking about. So let's take this guy, for example. All right. We're still going to call CACL2, or we're still going to name the metal first, followed by the anion. Okay. So cation followed by anion. And so what is that? That'd be, again, that would be CA. two plus. Remember, this is a group two metal, all right? And that should make some sense because why? There are two chlorides on that, all right? So it takes two chlorides to make a neutral compound, all right? So they, and chloride carries a negative charge, all right? So that, again, they kind of support each other, all right? So how do we name this? This would be our calcium ion. And this would be our chloride. Okay, remember we dropped the I-N-E and add I-D-E, ion, right? So this would be called calcium chloride, okay? And then what can we see? We see this little kind of, this symbol, right? This little dot here, okay? And that dot is telling you. that the waters that follow it are a part of that compound. All right. So again, you're going to be dealing with hydrates probably in lab would be my guess. All right. So you always want to remember when you see some compound, some inorganic salt, all right, followed by this dot kind of symbol followed by some number of waters, that water is a part of that compound. That compound is called a hydrate. Okay. And so How do we do this? Well, what do we need to do? The water part is called hydrate. Okay. That's, that's easy. All right. So calcium chloride hydrate, but we have to tell people, all right, our audience, whoever it may be, how many waters are actually there. Okay. So incomes are prefixes. Prefixes are listed over here. Okay. All right. So if it's one, all right, it's monohydrate. Okay. And again, look at the formula. We're not telling them there's a one. We're not writing one out front. We don't need to do that. It's redundant, okay? So we put our dot and we put one water molecule, H2O. All right, so this would be, in this case, ammonium oxalate monohydrate. Going to our calcium chloride example, calcium chloride di, okay, for two, hydrate, all right? And then sodium. acetate, trihydrate, all right? So there are three water molecules in that case, so on and so forth. So tetra, penta, hexa, hepta, octa, nana, and deca, all right? So you guys will want to kind of commit, all right? So learn these prefixes, all right? Because you'll need them when you're naming these hydrates, all right? And they also come into chemistry in other places as well, all right? Okay. But a big takeaway here is that the symbol is telling you that those water molecules, however many of the number is in this case is a hepta. All right. They are an integral part of that compound. They are a part of that compound. Okay. All right. So that's naming our, our hydrates. All right. So now let's think about some sample problems. Okay. So What we want to do here is take our formulas for this first one. We want to name the following ionic compounds. We want to go from formulas, okay, to names. Whereas down here, we want to go from names to formulas. All right. We want you to be able to go back and forth. Okay. All right. So let's take a look. All right. It's really useful to have your periodic table around. for these, okay, kind of help you continue to kind of get familiarized with the periodic table and where these different elements fall. But if you're looking at magnesium and bromine, all right, this is a group two metal, all right, so it's a main group metal, followed by our group seven, okay, so it's the halite, all right, so they're both main groups. All right. So main group metal with a main group nonmetal. All right. And therefore, this is a type one binary ionic compound. Again, binary telling us that there are two different elements that are making up that given compound. All right. So the question is, how would we name this? All right. So, again, let's think about how this formula came about anyway. All right. So we got a. Group two. So we got our two plus. All right. And we have bromine. All right. It's a halogen. It's one away. So it's going to form a negative anion. Okay. So where does this compound formula come from? Well, again, it's magnesium has two plus cation. So to neutralize that out, all right, we're going to need two of these bromines. That's again, where our magnesium, Br2 is coming from. That's where our formula is coming from. Again, the subscripted two tells us that for every magnesium in this compound, there are two bromines. All right, so how do we name this? Well, again, this is magnesium. I'm going to shorthand it, magnesium ion. Again, this is our anion. What do we want to do? We want to drop the ending of the name. We want to keep the root of the element, drop the ending, and add Ide. So this would be bromide. right? Ion. And if we're going to name this, we just merge the two names, the name of the cation followed by the name of the anion. So this would be magnesium bromide, right? Again, keep that IDE ending there. All right. Now, what do we have here? We have V3 in five. Well, if you're looking, all right, where's V? All right. V. is our third element, okay, within the one, two, three, the fourth period, all right, it's the third element within our transition metals, all right? So this is vanadium, okay? So vanadium is, all right, it's a transition metal, all right? And it can form multiple charge states. In fact, I believe people have found vanadium all the way from a plus one, all the way up to a plus six, all right? So... So because it can adopt multiple charges, we got to think about how we're going to name that. Remember, this is a type two binary ionic compound. And when we're talking about type twos, we're talking about transition metals. These guys can form multiple charges. So we need to indicate that charge with our Roman numerals. So the question is, how are we going to figure out what the charge is on that vanadium? Okay. Well, remember what I told you, the anions, right? The main group anions form very distinct, okay? The monatomic anions form very distinct charge states, okay? So what we do is we look at nitrogen. Nitrogen, all right, is a 5A. It's in group 5A. It means it's three away from the next noble gas. So what's it going to want to do? It's going to want to adopt a three minus charge. So nitrogen is going to be three minus, okay? So this is... nitride. Again, it still has an IDE, a nitride ion. Now we know that V is vanadium. So let's just write that out. Vanadium, if I can spell vanadium. What we're trying to do is figure out the charge and then nitride. Okay. Keep that ID ending. All right. All right. So now what we do, we're going to let this nitride anion kind of guide us to figure out what the charges on the vanadium. Okay. So what do we have? We have five of them. We have five nitrites. So what can we do? We know each of them adopts this three minus, so we can take five times three minus. Okay. Again, what is our goal here? When we combine the vanadium, all right, cations with these nitride anions, we want there to be a net overall zero charge. Okay. And what are we trying to solve for? Well, look, we have three vanadiums. So we got three of those times whatever their charge is. We just call that X. And what do we need to do? We just need to solve for X. So we get three X minus. 15 equals 0, 3X equals 15, and therefore X equals 5, okay? So we have a 5 plus charge on our vanadiums, okay? So if we're going back to how we name this, we would call this vanadium 5, all right? Roman numeral 5 in parentheses, nitride, okay? Vanadium 5 nitride. Now let's move on, all right? So now what do we have? All right, we're kind of mixing it up. We have another transition metal. This is manganese. Again, that's in one, two, three, period four on the periodic table, five in, all right? It's just past chromium, all right? And it is bound to, okay, acetate, okay? So here we see acetate for the first time. What we can do is we can go back to our little table, take a look at acetate. And what you see is acetate always... adopt a minus one charge. Okay. So again, following our rules for naming, this is going to be manganese. We're trying to figure out the charge because we know it's a transition metal. All right. Acetate. Remember the polyatomic anions or cations, we just use the name. We just use their name when we're actually doing the naming. Okay. So there's nothing fancy there. Acetate is acetate. All right. So if each of these acetates is carrying a negative charge and there are three of them, okay, what do we have? We have three and we want to make something neutral and we only have one manganese. So we'd have one times whatever X is equals zero. So we'd have Three minus. plus X equals zero, X would equal plus three, okay? So in this case, that manganese is carrying a plus three charge or a three plus charge. And so we put in Roman numerals in parentheses, okay? Manganese three acetate, okay? And then what can we do, okay? We can move on to D here. And now we have cobalt. All right. So cobalt again is in period four. It's another transition metal which follows iron. Okay. So we got to figure out what the charge on that cobalt is. Again, what are we going to do to figure that out? We're going to let the anion help us, right? The anions have very predictable charges. All right. So again, fluoride, all right, carries a negative charge on it. Okay. So therefore, if there are two of them for every cobalt, that cobalt must have a two plus charge. Okay. So how are we going to name this one? So we're going to call it cobalt two fluoride. And now we need to think about, all right. The fact that, or recognize the fact that this is, is a hydrate. Okay. These water molecules are an intimate part of this compound. All right. Again, that's what the symbol is telling us here. Okay. And so there are four of them. What's the prefix for four? It's tetra and then water hydrate. Okay. So we have cobalt two fluoride tetra hydrate. Okay. Awesome. All right. So let's move down now and talk about going from a name to a formula. Okay. So we have rubidium sulfide. Well, where's rubidium? Rubidium is a group one. Okay. So it's going to adopt a plus one charge. All right. This is a type one binary ionic compound. All right. So rubidium elemental symbols, RB stops a plus charge. Okay. And sulfide. So sulfur, it's an anion of sulfur. Sulfur is a group 6A. So it's going to adopt a 2-charge. So how do we go about figuring out what the formula is here again? I've been talking to you basically using logic. We want something that's neutral overall. That's our goal here when we're writing formulas. And if we have an anion that has 2-charge on it, and we have a cation with a plus charge on it, it's logically going to take two of those cations to balance out the charge that's coming from our anion. So this would be rubidium two. That's what that subscript tells us. There are two rubidiums for every sulfur. Okay. So RB2S. Okay. Now the other thing some of you may know about, all right, is this kind of crossover rule, or what you can do is you can take the number of the charge, all right, so the magnitude of the charge, and kind of carry it over as the subscripts. And that works in this case. So that would be RB2 and then S1, okay? Now, we don't ever put the 1 there because just by putting S, it tells us that there's at least 1, all right? So it works in this case. All right, so that's the crossover method. So you can use a logic method or you can use this kind of crossover method. Now there's a little trick to that that we'll see here. All right, so now we have lead for oxide. All right, well, this Roman numeral four is telling us that the lead is carrying a four plus charge. Again, it's listed first, that's our cation, followed by oxide. Oxide again is this group 6A. just like sulfur. So it's going to adopt a two minus charge. Okay. So if we're using this crossover method, what would we do? We'd take that four, move it over here by the oxygen subscripted after the oxygen. And this two would be after the lead. So it'd be PB2O4. Okay. PB2O4. Now, technically, all right. This isn't wrong, but it's a really bad representation, okay? Because what we want to always do when we're kind of reporting our formulas is use the lowest divisible number, okay? So in other words, what can we do with both of these numbers? We can divide them both by two, all right? We can simplify this formula, all right? So that would be PbO2, okay? PbO2, all right? So the crossover method will almost get you there, but not quite. Because if you put this on an exam, technically speaking, this would not be correct. Okay. So you want the whole, the visible number. All right. When you're talking about these ratios. Okay. Or you can just use the logic. All right. Well, if there's a four plus charge coming from the lead. All right. And a two minus charge coming from the oxygen. It's going to take two of these oxides, if you will. All right. To. balance out the charge from that lead four plus cation. So again, that would give us PBO2. Okay. All right. So that's that one. Well, how about this ammonium phosphite? Okay. Well, let's take a look here. Ammonium. All right. Is one of our polyatomic. uh, cat, uh, cations and phosphite. All right. So if we go back here, remember we talked about phosphite. All right. So part of this oxy anion series with phosphate. All right. And so what you can see here, this is also in this table is we have phosphite right here. All right. So let's just take a look at these, uh, two, uh, polyatomic ions. All right. Well, the ammonium is carrying a plus charge. All right. And the phosphites carrying a three minus charge. So again, when we're merging these guys together, we want something that's overall neutral. We want our compound or our formula to have an overall neutral charge. So therefore it's going to take three of these ammoniums for every one phosphite. So how do we write that? So we have NH4 and we said, it's going to ease each of these carry a plus one. He's carrying a minus three. Okay. And what do we want to do? We want to balance that out. Well, we need three of the ammoniums for every one phosphite. So what we do is we put this whole group of, of atoms, right? This grouping of atoms is polyatomic cation in parentheses, and then say, put a three, a soup, a subscripted three that tells us that there are three of these units, if you will, for every phosphite. Okay. So again, that would be PO3. Now when we're merging these guys together, again, this tells us about the ratios of how these guys are coming together. Since there's only one for the phosphite, we don't have to put the parentheses there. We can just write that down. All right. But there are three of these. So we do have to put the parentheses and indicate that there are three of them. And the other thing you'll see is that, and this goes for all of these formulas, we're not writing the charges anymore. Okay. We're putting these things together so that the charges. balance each other out. So therefore there's no charges to indicate in these formulas. Okay. All right. So that's, that's ammonium phosphate. How about copper one sulfite? Okay. Sulfite monohydrate. Okay. So copper, all right. It's clearly a transition metal and it is, is a period four. All right. It's right next to zinc. So it's number nine in our first row of transition metals, right? So copper. All right. We know it's carrying a plus charge. So we'll put that there. Sulfite. Okay. We can go back here. You can see sulfite. It's right here. Okay. You can also, again, find it on your table. SO3 2-. Okay. So we're going to write that down. SO3 2-. Okay. And it's a monohydrate. Okay. All right. Well, how do we merge this copper and this sulfite moiety? Okay. Well, again, sulfite carries a two minus charge. So it's going to take two coppers to balance that charge out. So we can write copper, two, sulfite. Okay. And then we have a hydrate here. So how do we indicate that there's going to be a hydrate? This little fancy symbol, this little dot. All right. And it's mono, mono meaning one. which means we don't have to put one, right? Hydrate. So we just write H2O. Okay. So this would be copper two, copper one sulfite monohydrate. Okay. All right. Now those are some sample problems. All right. Now here are some participation questions. All right. Again, we're going to go from the formula to the name. All right. And it's really important to also be able to go from the name to the formula. I hope you found this useful. All right. And if you guys have any questions, don't hesitate to reach out. I'm happy to help. And I also hope you have a great rest of your day.

Binary meaning two things, okay? So generally, it's a metal and a nonmetal coming together, okay? This doesn't necessarily have to be the case.

Because we talked about in the last lecture topic video, we talked about polyatomic ions, where these groups of covalently bound atoms somewhere in the process of forming these bonds have either lost or they have gained electrons. So we can form these polyatomic cations and these polyatomic anions. Well, these things can also take part. in ionic compounds. And the other thing we want to talk about in this lecture topic video is how do we name hydrates, all right, where we get these metal or these inorganic, I guess is what you would call them, inorganic salts being formed.

And sometimes we get these waters that kind of either bond directly to the metal or to the metal complex, but they bind in a very defined ratio. And essentially as these things crystallize, they become part of the crystal. lattice, right? So they become part of the compound. So we want to talk about how do we name those things.

But the first thing we want to talk about are how do we name our binary ionic compounds, okay? And so we got two types of these. There's this type one and there's a type two.

The type one, all right, is dealing with cations that can only adopt a single charge. So when we're talking about this, these cations are interacting with our non-metal anions. And so what metals are going to actually adopt only a single charge?

Well, remember, it's primarily going to be our main group elements, our main group metals. So our group 1A, our 2A. and our 3A metals.

Remember, the 1, 2, or 3, if you want a shorthand, right, remember that kind of tells us the types of charges that these metals can adopt. Remember, they're metals, they want to donate their electrons, all right? And by doing so, they move backwards so that they get the electronic configuration of the noble gas that precedes them, and that's stabilizing.

So again, our group 1As, what do they want to do? They want to lose one electron. All right.

So what you can see is they all form, all right, a single plus charged cation. All right. Our two A's for the same argument form two plus cations, whereas our group three A's form our three plus cations. All right.

So when we're talking about our type one binary ionic compounds, these are the metals that we're typically working with. And what are they doing again? They're interacting. with these non-metals. And remember these non-metals, right, they have much higher electron affinities.

In other words, they want to accept electrons. It's energetically favorable for them to do so. And by accepting these electrons, what they do is they move forward. So if they adopt the electronic configuration of the noble gas, all right, that follows them. So we get these binary, these type one binary ionic compounds.

All right, well, we're naming these things, the cation, all right, it doesn't matter if we're talking about the formula or the name. So the chemical formula or the name, the cation is always listed first, followed by the anion, okay? Cation first, anion second. Now, how do we name our cations? Well, our cations are actually quite easy to name.

What we do is we just take the name of the metal and we add ion to the end of it. For example, If we look at lithium, lithium forms a plus one cation. This cation would be called lithium ion, right? Sodium would be sodium ion. Magnesium would be magnesium ion.

Aluminum, aluminum ion, so on and so forth. It's actually quite easy to name our monatomic cations, okay? Now, our monatomic...

and answer are a little bit different. All right. Cause what we want to do is we want to take the element name.

All right. So nitrogen, oxide, fluoride. And what we want to do is drop the ending of that name and add the ending I-D-E.

All right. So, for example, we have fluorine. All right.

What we want to do, and many times you see this I-N-E ending. OK, what we want to do is we want to drop that. and make it fluoride, okay?

So that's I-D-E. And then what do we want to do is we want to add ion to it. So if we have F minus, what would we have? We would have a fluoride ion, okay?

So let's look at oxygen. Well, oxygen, okay, it's a little bit different, all right? But we're going to keep the root name. So the OX, it'd be oxygen.

And what we would do is drop the YGEN and make it oxide. All right. And then nitrogen would go to nitride.

What you can see again is all these guys have this IDE ending. Okay. And then we add ion to the end of it. All right.

So that's pretty straightforward for our monatomic. cations. We take the name of that element, whatever that metal is, name it, and then add ion to the end of it. When we're talking about our monatomic anions, we take the root of the name.

We drop the ending off of it and add this IDE followed by the word ion. Well, now how do we put them together? Well, what we would do is we just merge the two rules together.

So for example, Let's think about LIF, okay? Well, again, we got to start thinking about these formulas. How are we coming up with these formulas, right? One of the driving rules here is that anytime you make a formula, all right, you want that molecule, that compound to carry an overall neutral charge.

So they should be neutral in nature. So if lithium, all right, has a plus one. Okay. And fluoride has a minus one.

Those two things will come together in a one-to-one ratio to make LIF, which is a neutral compound. Okay. Well, how do we name this? All right. Well, this would be called lithium.

It's just the cation name first, fluoride, lithium fluoride. Okay. And so again, merging the two names. The metal is the name of the element followed by ion.

The non-metal anion is the root of that non-metal. Drop the ending, put IDE on there and ion. And then when we want to put these things together in a compound, we would call this lithium fluoride.

All right. They're no longer ions. So we drop the name ion completely. All right.

So let's see here. Can we make up another example? How about merging? Let's merge calcium with oxide.

Well, what would our formula be for that? Well, in this case, calcium cation or calcium ion carries a two plus. Okay. Again, these charges are very predictable. Main group element charges are very predictable.

We got calcium two plus and we have oxide, which is O2 minus. All right. So again, those charges cancel each other out.

All right. And so what they would do is they would come together in a one-to-one ratio. So we could get calcium oxide.

And we're dealing with a calcium ion and oxide ion. And so what we would do, we'd name it, again, metal first, followed by the anion. It would be calcium oxide.

Now, you'll notice that... I just because I'm just writing quickly. All right.

Not really paying attention to this. They're capitalized. I capitalize them. But these names do not need to be capitalized. OK, so calcium.

These are not proper nouns is better written like this. And lithium is better written like this. Just so you guys are straight on that. So these are our type 1s.

Now, we also have type 2s. Well, the difference here is that when we were talking about our type 1s, these are metals that have defined ionic charges. They carry a defined charge. So our group 1As, again, form these plus 1s.

Our group's 2As, 2+, so on and so forth. Well, now what happens when we get to… Our transition metals, okay, our transition metals. Now there's exceptions, all right?

There's exceptions like zinc, cadmium, and silver. They're transition metals, but they only carry a defined charge, all right? Zinc is two plus, cadmium is two plus, silver is plus, all right? But one of the defining kind of features, if you will, of these transition metals is that they can adopt.

multiple charges okay they can adopt multiple charges and so when we're talking about type two binary ionic compounds that is what we're talking about we're talking about our primarily our transition primarily not always transition metals all right and because our transition metals are bonding with these these um anions all right and we we know because they're transition metals they tend to be able to adopt multiple charges, we have a special way of representing that. We have to represent that by using these parentheses and then the charge listed in Roman numerals. So for example, iron three, okay? Iron three would be written as iron one, two, three.

Again, the name of the metal All right. Followed by the the charge on that metal. OK.

In Roman numerals, in parentheses, followed by ion. So this would be an iron three ion versus SN4. OK, this would be 10 for ion.

OK. And our nonmetals are named just like. what they were before. Our anions are named just as they were before. We take the name of the monatomic nonmetal.

We drop the ending of it. So we're going to keep the root of that name. We're going to drop the ending and add the IDE. Okay. And so let's take an example here.

All right. What if we have FeCl2 and FeCl2? C L three.

Okay. So we have a, a transition metal iron in this case. All right.

For both of them followed by our anion, right? What's our anion in this case, it is chloride. All right. So chloride right here.

So if we just wrote it like this, there's really nothing that distinguishes the two, although they are very, very different compounds. Okay. And they're very different compounds because that metal is in a different ionic state.

All right. So how do we figure out what that ionic state is? Right. So when you're dealing with these compounds that have a transition metal, and again, because the transition metals can adopt multiple different charges. All right.

What I would tell you, the rule of thumb that I always tell my students. is let the anion guide you, okay? Let the anion help you figure out what the charge is on that transition metal.

So what do I mean by that? Well, again, these non-metals, these non-metal anions, they form very defined charges, right? So nitrogen forms a minus three, and that's because if it adopts or essentially accepts three electrons, it moves over one, two, Three positions on the periodic table. It gets the electronic configuration of the noble gas that follows it. Very stabilizing.

All right. So group 5As will want to accept three electrons. Okay. So they'll form three minus anions. 6A.

So oxygen and sulfur are two big ones here. All right. They are two away from the noble gas that follows them.

So they would like to adopt two electrons. Okay. So they always form.

These two minus. anions, all right? And then as we move through 7A, all right, these are our halogens. Our halogens are only a single step away from the noble gas that follows them.

So what do they want to do? They want to adopt these minus one charges, all right? So because our anions, in this case, all right, carry very defined charges, we can use that. And knowing the formula, we can use that to determine, all right, what the charge on the metal center is.

Okay. So again, if chloride is carrying a minus charge, and if we're talking about FECL2, and there are two of them, right? That means that those chlorides, okay. And that two out front, that's being insinuated because of that two right there, that little subscript two tells you that there are two chlorines or two chlorides bound to a single iron. That's what this kind of nomenclature means here.

But if we have two of those and each of them carry a negative charge and our goal, our goal always is to make a neutral compound. That tells you that the iron has to have a two plus charge. So when we're naming this, it would be iron to chloride.

Now, again, let's look at iron. iron chloride where there's three chlorides. Okay. Well, again, now we have three chlorides that gives us a total of three minus charge.

All right. And we want that one iron to kind of neutralize that. All right. So therefore that iron has to carry a three plus charge. So this would be called or named as iron one, two, three iron, three chloride.

Okay. So this is our type two. Okay.

Again, type twos are dealing with an anion, a monatomic anion. All right. Very predictable charges.

And it is bonding with some cationic species that is coming from a transition metal typically. Okay. And so what you can do again is you can let the anionic charge help you determine what the charge is on that metal center. Okay.

And again, I say that this happens a lot, all right, with our transition metals, but they're not the only ones because you can look here, all right, these are main group, so tin and lead, and you can see that both tin and lead are capable of forming more than just a single charge, okay? But typically speaking, anything in the main group, all right, again, typically, not always, there's exceptions to almost any rule you can think of, the typically main group. elements, whether they be metals or non-metals, tend to form very defined charges. Okay, so that's our type one and our type twos.

Now, we also said that we have these polyatomic ions, okay? Again, they're all listed here. There's 20, okay?

And these things, in the process of forming these molecular bonds, these covalent bonds, all right, they have gained or they have lost an electron somewhere, okay? Again, most of these are polyatomic anions, all right? That's these guys, all right, here.

Again, because of the acetate, all right, there's multiple ways people list that, so it's got three boxes, right? But as you can see here, most of these are polyatomic anions. So as these covalent bonds are being formed between these different... atoms, all right, electrons were gained in this case.

Okay. So all these guys carry some negative charge. All right.

And, but we also have some polyatomic cations as well. So hydronium and ammonium. So that's these guys up here at the top. All right.

So we can just circle these here. So we got a couple of polyatomic anions. Now, remember, we want you guys to know these. Okay. So there's, there's 20 here.

Um, and I'm going to hopefully in this next slide, take you through some trips that will at least help you with half of them. Okay. That's the goal is for me to give you some tips that'll help you with at least half of them. Well, how do we name things with polyatomic, uh, anions or polyatomic cations? So let's think about sodium, uh, interacting with cyanide.

Okay. Um, well, sodium, all right, is a, uh, group one metal. All right.

So it's an alkali metal. So it carries an Na plus, right? Carries a single predictable charge, okay? And let's say it's interacting with this polyatomic anion.

cyanide. All right. C and minus. Well, again, we want to make this neutral compound.

So when we're writing a formula for this compound, all right, we put them in a one-to-one ratio. Okay. And again, we, anytime we have one of something, you don't have to indicate that.

All right. So what we would do is we just write sodium cyanide. Okay.

Now, how do we name it? Well, it's just like I said, all right, we have, how would we name this? This would be our sodium ion.

This would be our cyanide ion. And so when we're putting them together, we would just call this sodium metal first cyanide followed by the anion. All right.

So sodium cyanide. Okay. So that's an example using a polyatomic anion.

Well, let's look at a polyatomic cation. So this is a really common one that we'll see. All right.

It's ammonium. And so let's say that ammonium, again, it's the cation. So it comes first, interacts with chloride. Okay. Or maybe it interacts with another polyatomic anion.

All right. Well, how would we name this? Well, again, this is ammonium ion. This is chloride, not chlorine, chloride.

We drop the end. We keep the root of the name, drop the end and add IDE. So that'd be chloride ion.

And so we would name this ammonium chloride. Okay. How about this next one? Well, again, this is our ammonium ion. And if we look up here, this is another polyatomic.

So let's find it in O3. All right. It's right there. Okay. And this is, so this would be called our nitrate ion.

And so when we put these things together, It's ammonium nitrate. Okay. We just use the name as it is for the polyatomic, either cation or anion. Okay.

So now can I help you with kind of memorizing or learning? I'm not a big fan of that word memorization. All right. Can we learn how to name these guys? Well, some of these is literally brute force.

Okay. So which ones do I think are brute force? It's about half of them, okay? Because there's no predictable patterns, all right, that I can kind of tip you off on. All right.

So the hydronium, this is one that you'll want to commit to memory. Remember, another way you might see this, all right, instead of H3O+, this is really because there is this H plus interacting with water. That's what gives us our hydronium. And remember this H plus is called a proton. This will become really important here before long.

Okay. So you want to remember that one. Cyanide is another one.

Oxalate is another one. Permanganate, chromate, dichromate, ammonium, hydroxide, carbonate, and then our acetate. Okay. Again.

all three of these acetate representations are perfectly acceptable. Hopefully one of these will click with you more than the others, or maybe you got them all down. Just be prepared to see acetate presented to you in multiple forms.

Now, what does that do? That leaves this whole middle, this whole middle swath of compounds, all right, that I can actually provide you with some assistance on how to memorize these things, okay? So these guys, Right here.

I can help you with trying to make some sense of these guys. So I kind of cheated. I wrote this stuff out already. All right.

And what you see is I line these things up in a very, very particular way. Okay. So what are these things called? All right. These guys that have some element or some nonmetal that's bound to oxygen.

Okay. These are called oxy. anions.

All right. So there's sulfur and then there's oxygen. Right.

And then it's an anion. So that's why it's an oxy. That's the oxygen part.

anion coming from that two minus. All right. So each one of these is an oxy anion. And what you find in nature is that some of these guys form what we call oxy anion series.

Okay. Meaning that if we're looking over here, all right, we get multiples of these sulfur containing. All right. I've already made a mistake here. Let's just rewrite that.

There's multiple of these sulfur compounds that contain different numbers of oxygen, all right? But they are carrying, okay, the same charge, okay? So in this case, this is a sulfur oxyanion series. We have a phosphate containing oxyanion series, a nitrogen containing oxyanion series.

And what we want you to know is one of these halogens, all right? So chlorine. But there's oxyanion series for not only chlorine, but there's one for bromine, there's one for iodide, so on and so forth. So as you proceed through chemistry, you will see that there are many more of these oxyanions that we're not expecting you to know right now. But how can we make some sense of these guys?

Well, within each of these series here, and there are four, so we got one, two, three, and four. There, there is a, one of these is, is more abundant than the others. Let's just say it that way. Okay.

In other words, there was one that was discovered first between, within all of these series. Okay. And what that, what I'd like to call that is the parent is the parent compound.

Okay. And because they were found first, typically because they're more abundant, what scientists did, what chemists did was give them the ATE. ending.

Okay. So this is a sulfur containing oxyanion series. So this would be called sulfate.

So it has the A-T-E ending. Okay. Sulfate.

So the one for the phosphorus containing one is the P-O-4-3-minus. That is phosphate. Okay.

And then nitrate. And then what do we have? Chlorate. Okay. Again, these are all the ones that are more abundant, more readily known, however you want to think about it.

All right. And I call these again, the parent, the parent always gets that A-T-E ending. Okay.

So there are 10 different oxy anions listed here. And I will tell you that if you know these four, you know, all 10 of them. Okay.

Of course, there's some rules that you kind of need to keep tucked away in the back of your head, but all of this is going to come back. Okay. So this is a good kind of preamble to things that we're going to talk about later.

All right. Now what you can see, what distinguishes one of these, the ATE ending from these other guys, it's literally just the number of oxygens. Okay.

So you sulfate has four oxygens, still has the same sulfur, still has that two minus charge versus this SO3 two minus, right? So nothing changes except for the number of oxygens. And what you see is that that is true in each one of these series, right?

The, the, the kind of the, the root element that makes up the series stays the same. All right. And the overall charge of these anions stay the same.

The thing that changes is the number of oxygen. Okay. So if we take what I call the parent compound, all right, or the ATE ending, or ATE containing compound, if we drop one oxygen from that, that is now sulfite. They have the ITE ending. Okay.

So if we have phosphate, the only thing that changes from PO4 3 minus to PO3, Three minus is the number of oxygens. We've lost one. So this is now phosphite.

Phosphite. We have that I-T-E ending. Then we have nitrate and we have nitrite.

And then we have chlorate. And then if we drop one of those oxygens, we have chlorite. All right. So that takes care of eight of the 10. Well, what's going on with this guy?

And this guy, right? Well, in one case, if we're looking at the parent, the ATE ending compound, all right, we've gained one oxygen in one and we've lost two oxygens in the other, all right? Well, when we gain one electron, one oxygen, right?

We call this now per, we add this prefix per-chlor-8, okay? So everything stays the same except for we add per, okay? The per prefix, right? So now we have per chlorate, chlorate, chlorite, all right? And now what are we going to add?

We're going to add, we've lost two oxygens relative to our A-T-E ending. What are we going to do? We're going to add hypo, hypochlorite. We keep the ite ending from the previous guy, the Cl2 minus. All right.

That stays the same. And now since we've lost, all right, one oxygen, one additional oxygen, we call it hypochlorite. Okay.

So this is what we see in bleach, for example, hypochlorite, sodium hypochlorite. So hypo meaning under or, you know, signifying like less. All right. So that's where the hypo is coming from.

So hopefully this little trick here, all right, with a little bit of practice will help you memorize or learn, okay, these 10 oxy anions. And again, this discussion is very pertinent to what we're going to continue to talk about as we proceed through the semester. Okay. So, and again, these rules follow. There are many, many, many, many more oxy anions that are out there.

Okay. That are. outside of this table that we've kind of presented to you here.

So now let's talk about hydrates. Okay. So what are hydrates?

Again, these are when we have these inorganic salts, okay. Everything we've essentially been talking about are inorganic salts. Well, sometimes when these things start to crystallize, what they will do is they will kind of suck up water or soak up water from the environment.

And that water becomes an integral part of that. compound. It becomes a part of the compound. Okay. And it's not like it's just randomly soaking up water molecules from the environment.

It always happens in a definite ratio or a defined ratio. Okay. And those waters again, either bind to that metal center. All right.

Or they bind to that metal complex in general. Okay. So how do we go about naming these things?

Well, what we can do is we can name the actual ionic part, just like we've been talking about. So let's take this guy, for example. All right.

We're still going to call CACL2, or we're still going to name the metal first, followed by the anion. Okay. So cation followed by anion. And so what is that? That'd be, again, that would be CA.

two plus. Remember, this is a group two metal, all right? And that should make some sense because why? There are two chlorides on that, all right?

So it takes two chlorides to make a neutral compound, all right? So they, and chloride carries a negative charge, all right? So that, again, they kind of support each other, all right? So how do we name this?

This would be our calcium ion. And this would be our chloride. Okay, remember we dropped the I-N-E and add I-D-E, ion, right?

So this would be called calcium chloride, okay? And then what can we see? We see this little kind of, this symbol, right?

This little dot here, okay? And that dot is telling you. that the waters that follow it are a part of that compound. All right.

So again, you're going to be dealing with hydrates probably in lab would be my guess. All right. So you always want to remember when you see some compound, some inorganic salt, all right, followed by this dot kind of symbol followed by some number of waters, that water is a part of that compound. That compound is called a hydrate.

Okay. And so How do we do this? Well, what do we need to do?

The water part is called hydrate. Okay. That's, that's easy.

All right. So calcium chloride hydrate, but we have to tell people, all right, our audience, whoever it may be, how many waters are actually there. Okay.

So incomes are prefixes. Prefixes are listed over here. Okay.

All right. So if it's one, all right, it's monohydrate. Okay. And again, look at the formula. We're not telling them there's a one.

We're not writing one out front. We don't need to do that. It's redundant, okay? So we put our dot and we put one water molecule, H2O.

All right, so this would be, in this case, ammonium oxalate monohydrate. Going to our calcium chloride example, calcium chloride di, okay, for two, hydrate, all right? And then sodium.

acetate, trihydrate, all right? So there are three water molecules in that case, so on and so forth. So tetra, penta, hexa, hepta, octa, nana, and deca, all right?

So you guys will want to kind of commit, all right? So learn these prefixes, all right? Because you'll need them when you're naming these hydrates, all right?

And they also come into chemistry in other places as well, all right? Okay. But a big takeaway here is that the symbol is telling you that those water molecules, however many of the number is in this case is a hepta.

All right. They are an integral part of that compound. They are a part of that compound. Okay. All right.

So that's naming our, our hydrates. All right. So now let's think about some sample problems.

Okay. So What we want to do here is take our formulas for this first one. We want to name the following ionic compounds. We want to go from formulas, okay, to names. Whereas down here, we want to go from names to formulas.

All right. We want you to be able to go back and forth. Okay.

All right. So let's take a look. All right.

It's really useful to have your periodic table around. for these, okay, kind of help you continue to kind of get familiarized with the periodic table and where these different elements fall. But if you're looking at magnesium and bromine, all right, this is a group two metal, all right, so it's a main group metal, followed by our group seven, okay, so it's the halite, all right, so they're both main groups. All right. So main group metal with a main group nonmetal.

All right. And therefore, this is a type one binary ionic compound. Again, binary telling us that there are two different elements that are making up that given compound. All right.

So the question is, how would we name this? All right. So, again, let's think about how this formula came about anyway.

All right. So we got a. Group two. So we got our two plus. All right.

And we have bromine. All right. It's a halogen.

It's one away. So it's going to form a negative anion. Okay. So where does this compound formula come from?

Well, again, it's magnesium has two plus cation. So to neutralize that out, all right, we're going to need two of these bromines. That's again, where our magnesium, Br2 is coming from. That's where our formula is coming from.

Again, the subscripted two tells us that for every magnesium in this compound, there are two bromines. All right, so how do we name this? Well, again, this is magnesium. I'm going to shorthand it, magnesium ion.

Again, this is our anion. What do we want to do? We want to drop the ending of the name.

We want to keep the root of the element, drop the ending, and add Ide. So this would be bromide. right?

Ion. And if we're going to name this, we just merge the two names, the name of the cation followed by the name of the anion. So this would be magnesium bromide, right?

Again, keep that IDE ending there. All right. Now, what do we have here?

We have V3 in five. Well, if you're looking, all right, where's V? All right.

V. is our third element, okay, within the one, two, three, the fourth period, all right, it's the third element within our transition metals, all right? So this is vanadium, okay? So vanadium is, all right, it's a transition metal, all right? And it can form multiple charge states. In fact, I believe people have found vanadium all the way from a plus one, all the way up to a plus six, all right?

So... So because it can adopt multiple charges, we got to think about how we're going to name that. Remember, this is a type two binary ionic compound. And when we're talking about type twos, we're talking about transition metals.

These guys can form multiple charges. So we need to indicate that charge with our Roman numerals. So the question is, how are we going to figure out what the charge is on that vanadium? Okay. Well, remember what I told you, the anions, right?

The main group anions form very distinct, okay? The monatomic anions form very distinct charge states, okay? So what we do is we look at nitrogen. Nitrogen, all right, is a 5A.

It's in group 5A. It means it's three away from the next noble gas. So what's it going to want to do?

It's going to want to adopt a three minus charge. So nitrogen is going to be three minus, okay? So this is...

nitride. Again, it still has an IDE, a nitride ion. Now we know that V is vanadium. So let's just write that out.

Vanadium, if I can spell vanadium. What we're trying to do is figure out the charge and then nitride. Okay.

Keep that ID ending. All right. All right. So now what we do, we're going to let this nitride anion kind of guide us to figure out what the charges on the vanadium. Okay.

So what do we have? We have five of them. We have five nitrites. So what can we do? We know each of them adopts this three minus, so we can take five times three minus.

Okay. Again, what is our goal here? When we combine the vanadium, all right, cations with these nitride anions, we want there to be a net overall zero charge.

Okay. And what are we trying to solve for? Well, look, we have three vanadiums. So we got three of those times whatever their charge is.

We just call that X. And what do we need to do? We just need to solve for X. So we get three X minus. 15 equals 0, 3X equals 15, and therefore X equals 5, okay?

So we have a 5 plus charge on our vanadiums, okay? So if we're going back to how we name this, we would call this vanadium 5, all right? Roman numeral 5 in parentheses, nitride, okay?

Vanadium 5 nitride. Now let's move on, all right? So now what do we have?

All right, we're kind of mixing it up. We have another transition metal. This is manganese. Again, that's in one, two, three, period four on the periodic table, five in, all right? It's just past chromium, all right?

And it is bound to, okay, acetate, okay? So here we see acetate for the first time. What we can do is we can go back to our little table, take a look at acetate.

And what you see is acetate always... adopt a minus one charge. Okay.

So again, following our rules for naming, this is going to be manganese. We're trying to figure out the charge because we know it's a transition metal. All right. Acetate. Remember the polyatomic anions or cations, we just use the name.

We just use their name when we're actually doing the naming. Okay. So there's nothing fancy there.

Acetate is acetate. All right. So if each of these acetates is carrying a negative charge and there are three of them, okay, what do we have?

We have three and we want to make something neutral and we only have one manganese. So we'd have one times whatever X is equals zero. So we'd have Three minus.

plus X equals zero, X would equal plus three, okay? So in this case, that manganese is carrying a plus three charge or a three plus charge. And so we put in Roman numerals in parentheses, okay?

Manganese three acetate, okay? And then what can we do, okay? We can move on to D here. And now we have cobalt.

All right. So cobalt again is in period four. It's another transition metal which follows iron. Okay.

So we got to figure out what the charge on that cobalt is. Again, what are we going to do to figure that out? We're going to let the anion help us, right?

The anions have very predictable charges. All right. So again, fluoride, all right, carries a negative charge on it. Okay.

So therefore, if there are two of them for every cobalt, that cobalt must have a two plus charge. Okay. So how are we going to name this one? So we're going to call it cobalt two fluoride.

And now we need to think about, all right. The fact that, or recognize the fact that this is, is a hydrate. Okay. These water molecules are an intimate part of this compound.

All right. Again, that's what the symbol is telling us here. Okay.

And so there are four of them. What's the prefix for four? It's tetra and then water hydrate. Okay. So we have cobalt two fluoride tetra hydrate.

Okay. Awesome. All right.

So let's move down now and talk about going from a name to a formula. Okay. So we have rubidium sulfide. Well, where's rubidium?

Rubidium is a group one. Okay. So it's going to adopt a plus one charge. All right. This is a type one binary ionic compound.

All right. So rubidium elemental symbols, RB stops a plus charge. Okay. And sulfide.

So sulfur, it's an anion of sulfur. Sulfur is a group 6A. So it's going to adopt a 2-charge. So how do we go about figuring out what the formula is here again? I've been talking to you basically using logic.

We want something that's neutral overall. That's our goal here when we're writing formulas. And if we have an anion that has 2-charge on it, and we have a cation with a plus charge on it, it's logically going to take two of those cations to balance out the charge that's coming from our anion.

So this would be rubidium two. That's what that subscript tells us. There are two rubidiums for every sulfur.

Okay. So RB2S. Okay.

Now the other thing some of you may know about, all right, is this kind of crossover rule, or what you can do is you can take the number of the charge, all right, so the magnitude of the charge, and kind of carry it over as the subscripts. And that works in this case. So that would be RB2 and then S1, okay?

Now, we don't ever put the 1 there because just by putting S, it tells us that there's at least 1, all right? So it works in this case. All right, so that's the crossover method.

So you can use a logic method or you can use this kind of crossover method. Now there's a little trick to that that we'll see here. All right, so now we have lead for oxide.

All right, well, this Roman numeral four is telling us that the lead is carrying a four plus charge. Again, it's listed first, that's our cation, followed by oxide. Oxide again is this group 6A.

just like sulfur. So it's going to adopt a two minus charge. Okay.

So if we're using this crossover method, what would we do? We'd take that four, move it over here by the oxygen subscripted after the oxygen. And this two would be after the lead.

So it'd be PB2O4. Okay. PB2O4. Now, technically, all right. This isn't wrong, but it's a really bad representation, okay?

Because what we want to always do when we're kind of reporting our formulas is use the lowest divisible number, okay? So in other words, what can we do with both of these numbers? We can divide them both by two, all right?

We can simplify this formula, all right? So that would be PbO2, okay? PbO2, all right? So the crossover method will almost get you there, but not quite.

Because if you put this on an exam, technically speaking, this would not be correct. Okay. So you want the whole, the visible number. All right. When you're talking about these ratios.

Okay. Or you can just use the logic. All right. Well, if there's a four plus charge coming from the lead.

All right. And a two minus charge coming from the oxygen. It's going to take two of these oxides, if you will.

All right. To. balance out the charge from that lead four plus cation. So again, that would give us PBO2.

Okay. All right. So that's that one. Well, how about this ammonium phosphite?

Okay. Well, let's take a look here. Ammonium. All right.

Is one of our polyatomic. uh, cat, uh, cations and phosphite. All right.

So if we go back here, remember we talked about phosphite. All right. So part of this oxy anion series with phosphate.

All right. And so what you can see here, this is also in this table is we have phosphite right here. All right.

So let's just take a look at these, uh, two, uh, polyatomic ions. All right. Well, the ammonium is carrying a plus charge.

All right. And the phosphites carrying a three minus charge. So again, when we're merging these guys together, we want something that's overall neutral. We want our compound or our formula to have an overall neutral charge.

So therefore it's going to take three of these ammoniums for every one phosphite. So how do we write that? So we have NH4 and we said, it's going to ease each of these carry a plus one.

He's carrying a minus three. Okay. And what do we want to do?

We want to balance that out. Well, we need three of the ammoniums for every one phosphite. So what we do is we put this whole group of, of atoms, right? This grouping of atoms is polyatomic cation in parentheses, and then say, put a three, a soup, a subscripted three that tells us that there are three of these units, if you will, for every phosphite. Okay.

So again, that would be PO3. Now when we're merging these guys together, again, this tells us about the ratios of how these guys are coming together. Since there's only one for the phosphite, we don't have to put the parentheses there. We can just write that down. All right.

But there are three of these. So we do have to put the parentheses and indicate that there are three of them. And the other thing you'll see is that, and this goes for all of these formulas, we're not writing the charges anymore.

Okay. We're putting these things together so that the charges. balance each other out. So therefore there's no charges to indicate in these formulas.

Okay. All right. So that's, that's ammonium phosphate. How about copper one sulfite? Okay.

Sulfite monohydrate. Okay. So copper, all right. It's clearly a transition metal and it is, is a period four.

All right. It's right next to zinc. So it's number nine in our first row of transition metals, right?

So copper. All right. We know it's carrying a plus charge. So we'll put that there.

Sulfite. Okay. We can go back here.

You can see sulfite. It's right here. Okay. You can also, again, find it on your table.

SO3 2-. Okay. So we're going to write that down. SO3 2-.

Okay. And it's a monohydrate. Okay. All right.

Well, how do we merge this copper and this sulfite moiety? Okay. Well, again, sulfite carries a two minus charge. So it's going to take two coppers to balance that charge out. So we can write copper, two, sulfite.

Okay. And then we have a hydrate here. So how do we indicate that there's going to be a hydrate?

This little fancy symbol, this little dot. All right. And it's mono, mono meaning one. which means we don't have to put one, right? Hydrate.

So we just write H2O. Okay. So this would be copper two, copper one sulfite monohydrate.

Okay. All right. Now those are some sample problems.

All right. Now here are some participation questions. All right.

Again, we're going to go from the formula to the name. All right. And it's really important to also be able to go from the name to the formula.

I hope you found this useful. All right. And if you guys have any questions, don't hesitate to reach out. I'm happy to help.

And I also hope you have a great rest of your day.

Transcript for:Naming and Understanding Ionic Compounds

Transcript for:
Naming and Understanding Ionic Compounds