Hi, we're going to talk about sections 3. 4 through 3.6 to finish out Chapter 3. So we talked about writing ionic formulas, and now we're going to look at how to name ionic compounds. So first, to name ionic compounds, you're going to name the cation, and then you're going to name the anion. It's a very simple rule. You name the positive thing, then we name the negative thing. So naming cations. If you're a main group cation, a main group, remember it means tall. Tall columns. Brain is malfunctioning tall columns. So your tall columns are going to be your main groups, right? So in the cations are just groups one, so group 1-2 and 13 for us, and they're just named for the element which they're formed. So sodium cations. It's just called sodium. Potassium ion is just called potassium now when it's by itself. So if you're not talking about in a formula, you put the word I on. After it. So you would want to make sure you're differentiating. Like if I tell if I'm a doctor and I tell my patient, OK, you need more sodium in your diet, there's an assumption there that it's sodium ion. But if I were being very particular, I would say sodium ion because telling them technically to eat sodium would be like. Telling them to eat something that would probably kill them. Sodium by itself, sodium atom is very dangerous. So the sodium ion is what we're consuming on a daily basis. So if it's by itself, put the word ion after. But when we're naming the compound, when it's with its anion, we just say the element name. So that's pretty easy. We just say the element name. Some metals we talked about earlier make more than one different charge and so we can't just say iron for example. I I can't just say iron chloride because iron has multiple charges. So my formula and my ratio of. Ions will be different depending on what the charge of iron is. So we are going to focus in this class only on the systematic name where we put Roman numerals in parentheses to tell the charge. Roman numerals that you need to know are going to be 123. 4IV5 which is V and six which is VI. You won't need to know more than six for this class, so if the charge is 2, we put two in Roman numerals after the word ion. If the charge is 3, we put 3 in Roman numerals after the ion. You may come into contact with common names. Usually we use OUS for the cation with a smaller charge and IC for the cation with the higher charge, so ferrous and ferric, but this is kind of confusing because for copper. For example, copper cuprous is +1, not +2, and cupric is +2, not +3. So it us doesn't mean two and ich doesn't mean three. So it's a little confusing, but I'm just saying you might have seen this already in like a supplement. I don't know ferrous oxide or ferrous chloride or ferric sulfate or something like that. That's what that means. You are only responsible for the systematic name though with the Roman numerals, and the Roman numerals tell the charge of that ion because it does have multiple charges, so you do have to say. Which one it is, and that's it. That's naming cations. You're either going to put the element name or you're just going to put the element name with a charge if it's not one of the tall groups, the ones we talked about. So here it's going to be all your tall columns, so group one. 213 and I want you to know zinc. And silver. They would follow under these main group ones and no Roman numerals. For these, because they always have the same charge no matter what. You don't have to say zinc 2, silver one, calcium 2, sodium one. You just say calcium, zinc, sodium, magnesium, potassium. And anybody that's not in that list I just gave you is this one. They need Roman numerals for to to tell the charge. They're a type 2 metal or a type 2 cavan. Don't worry about the the types, just need to know which ones need Roman numerals, which ones don't. If if these are the ones that don't need Roman numerals, if it's not one of those, then it does need Roman numerals for the metals. The non metals never use Roman numerals. So here are some others that have Roman numerals, just so you can kind of see the the common names for them. Again, you don't have to use the common name, so it is there in case you're curious. Anions. So we talked about this a little bit already, but when we change the element that's an anion or a nonmetal into an ion, we change the ending of it. We add IDE as the suffix. So bromine becomes bromide, chlorine becomes chloride, nitrogen becomes nitride, phosphorus. Becomes phosphide, sulfur becomes sulfide. So this is a list of just the common ones. Um, I think that these would be the you'd be good for these. I think there are others like selenium would be selenide, right? You could you could technically do them again. You have a multiple choice exams. And quizzes for this class, so pretty easy to to find that out. So that's it for anions. We'll we'll talk more about polyatomic anions a little bit later. But cations, you just name the metal. If it's a special metal that has more than one type of charge, you put the Roman numerals for the charge. And then anions, you just put the IDE on the end. So the rule for naming ionic compounds is name the cation and the anion if it's a main group metal. Which is we're going to include group one, group two, group 13, zinc and silver. We're not going to put the charge, we're just going to say the name of the metal, and then for the anion, you'll say the name of the anion, which is the name of the element with the IDE. So here are those examples. We don't have to specify how many ions are in the formula, so you don't have to say anything to tell me there's two chlorines. I know there's two chlorines because magnesium is +2 and chlorine is -1. There has to be two chlorines. You don't have to tell me anything but the two elements we put here. The two ions, the cation and ion. If it's one with variable charge, you're going to tell me what the charge is, but you're going to have to figure that out. So let's look at how to figure out that out. So for CU CL2 we need to name it and we can already kind of guess what the name will be. We know CU is copper. So we may know the name is going to be copper chloride. Now copper is not an element that's in group 1-2 or 13 or zinc or silver. So copper does have Roman numerals. The Roman numerals are going to go in for the charge of the copper and then I have chlorine which is just going. Going to be turned into chloride for my name, but I got to figure out what that charge is on the copper. So let's let's take a look at that. If I have CU and CL2, I got to figure out what is that charge on that copper. So let's kind of set up what we don't know. We don't know the charge of the copper. I do know it's. Positive, but I just don't know what positive it is and I always know the anion. Chlorine is always -1. And now I have to think about how many chlorines I have and what does the charge of copper have to be? Because remember the rule is we have to balance it out and it has to add up to 0. So there are two chlorines here. So there are two chlorines and there's one copper. So if there's one thing I don't know and there's two things I do know, well, I have to get them to add up to the same number, right? Two negative ones make -2. So what does the copper have to be? If they have to be equal in opposite charges, the copper has to be +2, so copper must be 2 plus because the only way to cancel out -2 is to put +2. Does that make sense? So you kind of have to draw it out and look at it and look at the formula and look at what you do know to figure out the unknown. One other way that I you can do this if you want to is to say one copper I don't know. +2 chlorines I know are -1 have to add up to 0. Here I was just saying they kind of have to add up to each other, like the number has to be the same. Here you're actually going to take into account the charge, make them add up to 0. And if you do this algebra out, you'll get X = +2, which is our. Charge for copper, so we put in copper 2 chloride. It's not copper one because there's one of them. Roman numerals tell me the charge, not how many there are. So it's copper 2 because the charge of copper is 2 if there are two chlorides that equal -2. The copper must be +2 if there's only one of them that balances out a -2. One of what makes a two? One of a two makes a two, if that makes sense. So they kind of are talking about this in the slide, like the cation has to have a + 2 to make the overall charge. So um. We could call this copper 2 chloride or cupric chloride. Again, you're not going to worry about the the common name. And then when we're naming it, we write the name of the cation, the positive 1st, and then the anion. Why don't you try this one? Pause it and try 10-4 oxide. Can you write the formula for that? Once you're done pausing, first write out your ions. So 10/4 means 10 with a 4. So we put a 4 here and then oxide O with a -2. How do we know oxide's a -2? It's in group 16. All group 16 nonmetals are -2. Now we have to make sure that the charges are the same number, so they cancel out. How many twos do you need to make a four? We need 2 oxides and 110. Does that make sense? How many twos to make a four? We need one. 10 four and we need two O twos because two O twos is -4 and 1 +4 is +4. Do you see how I'm getting this this numbers from? I hope 2 negative twos make a 4 and 1 +4 makes a four, so least common multiple of. Four and two is 4, so they both have to equal 4. Because we need two negative twos, we write the formula 202, so 110 that's your +4 and two OS that's your -4 two negative twos make. A -4. This takes practice, so don't be too frustrated if you're not immediately understanding. You could do the the crisscross, but if you crisscross this one, you got to make sure to reduce it so you'll get down to the correct answer. All right, moving on to non math stuff, a little less content here really quick, just physical properties of ionic compounds. So ionic compounds because they have their attraction, it's a positive charge, negative charge, really strong attraction. They have very high melting and boiling points. It's really hard to separate those particles because they really like each other now. But when they dissolve in water, they actually really like water a lot, and they'll actually break apart in water. So when the ionic compounds dissolve in water, most of the most of them, they. Most of them dissolve well in water. Some of them don't dissolve quite as well in water, but most of them do dissolve pretty well. They separate into their ions and they make a solution that is got charges in it. We call this an electrolyte. And so if you're like, oh, I need to drink some electrolytes, it's probably ionic compounds, or it is ionic compounds dissolved in water to give you a solution of water. A solution is just a mixture. A solution can be a homogeneous mixture of water with charges dissolved. So like all of these little these are pluses. And these are minuses, so we get this. Charged particles floating around in water and we call those electrolytes because they can conduct electricity. When we're naming ionic compounds, you're gonna find that there are these polyatomic ions that are hanging around. So it's not just chloride and oxide and and sulfide. We got a bunch of other. Ions that are involved in things. This is from your memorization list. You do need to memorize the formula including the charge and the name, and then I have a few more down here to add to this list that I know you may see. This one for acetate, you can also write it C2H3O2 minus, or you can write it CH3COO minus. There's a couple different ways to write that acetate one. The rest of them, this is the way they have it is fine, but make sure you have your flashcards and you're memorizing not just the the CO3, but the CO32 minus. You got another charge so you can use it to build your formulas. So you'll need to get on with memorizing those if you haven't already. We're going to write the formulas exactly the same with polyatomics as we did with regular stuff. So if we have sodium with a + 1 charge and nitrite with a -2 charge, we just need one of each, right? One +1 and one negative. So I put one in A and I put one in O2. If I use parentheses around a polyatomic, it means I have more than one of the polyatomic. If I only have one of it, I don't need parentheses. I just say, hey, there's one in O2. Here I have two plus for barium and two minus for sulfate. How many twos do we need to make a two? One. So one barium and one sulfate. Again, I don't put parentheses around it unless I have more than one. So if you just have one of the polyatomic ion. Just leave it alone. So this is one sodium, one nitrite. That's one barium, one sulfate. We're never going to be naming something or writing things for ionic that have more than two pieces. Ionic is always cation. And then anion. There's not three different pieces to this, even though there's three elements. So memorizing those polyatomics and recognizing them is going to be really helpful when you have unequal charge. So if we want to put magnesium with this one hydroxide. We need two negative ones to balance out a +2. Don't look at the formulas, look at the charges. I need two negative ones, whatever it is, to balance out a +2. So I'm telling you in the formula here, two of this whole group, that's my negative ones. So two negative ones make a +2. So if we have more than one polyatomic, you do put parentheses around it and you put the number that you want of that group on the outside. But no parentheses if there's just one of them. But if you do need more than one, you do have to put parentheses. So if you did MGO H2, that's not the same. This is telling me two Oh's. This is telling me two HS and one O, and so that's not necessarily the same. as the previous formula. When you're naming ionic stuff, you don't do anything to the polyatomic or sorry. When you're naming polyatomic stuff, we don't do anything to the polyatomic. We don't write Roman numerals, we don't change the name, we just write what it is. So if you see sodium and bicarbonate hanging out, we just call it sodium bicarbonate. If you see aluminum and sulfate hanging out, we just. Called aluminum sulfate. We don't do anything to the name of that polyatomic that you just spent a bunch of time memorizing. And then here's a nice little list of ionic compounds, kind of a flow chart. Ionic compounds are metals and nonmetals, cations and anions kind of color-coded there for you. First you name the cation. If it has a fixed charge or only one charge, you just use the name. If it has a variable charge, you put Roman numerals for the charge. And then the anion. If it's just the one element anion, you just change it to IDE. If it's polyatomic, you just leave it alone. Here I know they're saying the eights and the ites, but you'll have those memorized, so you don't need to worry about knowing like this rule. You just leave it alone. Leave the name the way that it was. There's a practice website for writing and naming formulas. I would highly recommend that you go on that. You can literally make yourself a quiz of however many questions you want and just constantly be practicing writing and naming formulas. Do only ionic ones for now. You can add in common, not uncommon polyatomics. You can make your own quiz there and we'll as we add more.