all right so let's look at big picture we spent the first part of chapter five going through a little bit of classifying and then we moved on to talking about formulas and why did we learn about classifying first because we have to be able to tell if something is molecular or ionic before we know what kind of formula we're dealing with with ionic formulas we dealt with charges with molecular formulas we're not going to have that worry and now we're also going to move on to covering naming and again we learn classifying first because we're going to have to know what it is before we can name it so we do have a rule system for different types of compounds but we also have a few common names now common names you could think of as nicknames these are compounds that we just come across on a regular basis that don't need the fancy systematic name now this we've seen a few times in this chapter is h2o by its strict naming rules we would call this dihydrogen monoxide but the common name is what we use we call it water there are only two common names that i want you to know and that is h2o is water and nh3 is ammonia now be careful with ammonia nh3 is ammonia and nh4 plus is ammonium it's one of your polyatomic ions so just be careful because they're similar ammonia and h3 ammonium and h4 plus now let's focus on ionic compounds first we're going to have two types of ionic compounds that we're going to deal with metal ions that form only one type of ion we called this before are dependable ions because they form only one type of charge now these are the ones like you would see in group one group two uh so your sodium plus your ca your calcium two plus your aluminum three plus these were the types that we memorize you could also see this called in your book invariant because they don't change now the second type is going to be metals that form more than one type of ion these are not dependable they can form multiple charges these tend to be transition metals in the middle of the table these have a variant charge meaning they can form more than one type of charge and these would be things like iron where iron can form fe2 plus but it can also form fe3 plus copper can form plus one or copper conform plus two so we'll have to use what we know to figure out what we don't or have some type of naming that we can get around these differences and define them so type 1 ionic compounds we went over these typical charges when i have type 1 invariant or dependable charges that don't change we had our alkali metals we had our alkaline earth metals we had zinc we had aluminum and we had silver the three big ones that i wanted you to memorize other than those first two columns type 2 basically anything that you see in the center of the table here that's shown as tan these are going to have variable charges transition metals okay so let's focus on binary compounds binary compounds are going to have just two elements now that's a little bit of a misnomer we may also see polyatomic ions show up in these very similar naming scheme but we'll get there but we're going to start with type 1 compounds which remember those are the ones that have dependable or invariant charges charges that don't change for the metals now we're going to go with the name of the cation or the name of the metal first and then the name of the anion plus ide so we're going to end in ide so let's start with these two examples down here name the formula cabr2 i'm always going to give you a periodic table on exams that has the name of the elements on it ca is calcium so let's start there so calcium and then br is bromine and i'm just taking these straight off the periodic table i haven't done anything with their names and the naming rule says we're going to take the name of the metal so this is good but here it says i'm going to take the base name of the anion or the base name of the second part of the name typically are non-metals or anions and i'm going to end instead with ide so we would call this calcium bromide now for ionic compounds i don't have to account for how many of these bromides i had so common misconception this would not be calcium dibromide i don't have to say anything about the two i can ignore the two i'm just focused on the identity of the two elements why because we just went through writing formulas for compounds like this if calcium is 2 plus because it's in group 2 if br is -1 because it's in group 17 then when i cross and bring down when i write out my formula we're going to get ca br2 so base the name on the element the elements not on the number of each atom when we're looking at ionic compounds let's look at k2o k is potassium and o is oxygen these are their names straight off the table we take the name of the metal that's good we take the name of the anion which we start with that and we're going to end an ide so instead of oxygen it's going to be oxide so it's going to be potassium oxide and again i didn't say anything about the two i just worried about the k and the o and that's what we focus on in ionic naming okay so we got a list of typical anions uh just to give you a feel for this second portion of naming where you take the base name of the anion and add ide so for fluorine you drop the ene and it becomes fluoride first sulfur you drop the ending it becomes sulfide so this chart here is going to give you a feel for how to end in the ide endings okay type 2 metal ion compounds so this is where we had variable charges this means these metals can form more than one type of charge to be able to specify we're going to use roman numerals now typically it's going to fall with either one two three or four we could go higher but typically one two three or four is going to do the trick especially in chem 90. so let's look at copper copper can form one of two different charges here we could either have copper plus one or copper plus two if we look at this first example cl is in group 17 so we know that chlorine has a -1 charge this is the anion side it's negative this is the cation side and it's going to be positive so i have one copper here i have one chloride here so over here one of these at negative one i'm gonna have negative one total charge over here i need this copper to balance it out so that copper has to be a plus one to balance it out so this in this example over here we would have copper with a one charge over here if i do the same thing i still have my negative side my anion i still have my positive side over here each of these chlorines are still going to be negative one but they're negative one a piece so two of these at negative one a piece gives me negative two total charge so over here this single copper has to balance that out so the copper has to be plus two so this would be a copper 2 over here so over here we see our naming rules for this i'm going to start with the name of the cation i'm going to put the charge of the metal and then end just as we did before with the name of the non-metal plus ide so over here i'm going to have copper parentheses this was copper one plus so i'm going to put copper with a i roman numeral one and then this is chlorine so we would end it with chloride ide the only difference over here is we would be looking not at copper one but here we found it was copper two plus so i'd put i i for copper two and i would still end in chloride so we couldn't just say oh i want you to go get copper chloride off the shelf you would have to specify whether you wanted copper 1 chloride or copper 2 chloride because copper is a type 2 metal because it can have multiple different charges that it can take on okay so let's uh do two more examples we'll try it out with fecl2 and fvcl3 cl again a negative one charge it's in group 17 two of these would tell me i've got negative two total charge over here with my anions now over here on my cations i need to balance that out i've got one iron to balance it out so that one iron has to have a two plus charge to balance out the negative two so this would be iron fe is iron whoa let's pretend i did not just misspell that that would be iron because it has a two plus and then cl is chlorine but we would end with chloride down here facl3 similar idea but here with my anions i've got three of these at negative one apiece so a total of negative three this fe has to balance it one f e at plus three would balance the charge so this is gonna be iron three chloride so the pattern again name the metal we named it iron fe name the charge of the metal it's either going to be plus two or plus three in this case and then the base name of the anion is chlorine and then we change the ending to ide or idea so typical metals uh you've got chromium chromium can be plus two or plus three and this chart just gives you the typical charges of ions you don't have to memorize this chart i'll have you figure out what you don't know based on what i've asked you to memorize now you do have an older name here if you see it that's great you can use this table to understand it a little better we just did an example on iron where we had iron 2 or iron 3 we use the roman numerals so focus here don't worry as much about the older names but you will come across them so iron two for example we would have called the compound that we named ferrous chloride for the iron ii or ferric chloride for the iron three so when you use the older naming system it just takes the place of the roman numerals but we're gonna focus on the roman numeral system okay ionic compounds with polyatomic ions it's a little more straightforward we use the same rules that we used before it's just we're going to use the endings of the polyatomic ions we're going to use the names themselves and we're not going to change it so let's look at cu no3 cu is a transition metal and because it's a transition metal that means it has a variant charge that makes it type two that's where we had to use roman numerals so if we look nitrate up on our polyatomic ion last nitrate is no3 minus and copper must have balanced that out so copper had to have been a plus one so we could name this cu or copper and the copper has a plus one charge and we would end with nitrate nitrate okay what we wouldn't name this is nitride nitride would tell me that i was looking in a different compound straight off the periodic table it'd be a compound between copper and nitrogen copper one nitrate because i'm ending an ate that tells me this is a polyatomic ion i'm keeping the name of the polyatomic okay let's try this guy down here now cl is chlorine but we've learned so far that we change the ending of the anion to chlor and then this is straight off our periodic table nh4 ammonium so this would be ammonium chloride there is a little space in here between the two halves of the name but ammonium chloride okay so good news the ionic naming definitely more complicated we're going to move into molecular naming molecular naming is based on prefixes so pause here for just a minute and write this all caps ionic no prefixes molecular naming use prefixes so when we looked at ionic naming we used charges charges took care of most everything for us in terms of how many we needed of our anions and our cations when we get to molecular compounds we're not dealing with charges anymore instead we have to use prefixes memorize these flash card them you've got to know these to be able to name your molecular compounds so let's start here we've got n2s i've got two of my nitrogens so let's start there we're going to take a prefix and the name of the first element so the prefix for two is die so i'm going to have dinitrogen so the prefix plus the name straight off the table the second half of the name i've got one sulfur so mono and then the base name of the second element plus ide so dinitrogen and it's not going to be sulfur it's going to be sulfide okay so next year we've got cf4 and here we have one of our element to start with so here's an exception an important exception it's the only time you can leave off a prefix you can leave off mono on the first element in the name so here in cf4 i wouldn't say this is monocarbon because mono's the prefix for one i would just say carbon and then the second half of the name i've got four so we need the prefix for four and that's tetra so it'd be carbon tetra and this is fluorine but we have to end an ide so it's going to be carbon tetrafluoride so let's name a couple of these some of these will be a little more familiar with maybe even this one here this is excuse me carbon dioxide let's see why this works out we don't name it monocarbon because we leave mono off the first part of the name we would just start with carbon and then die is the prefix for two off the previous chart that we looked at and then oxygen becomes oxide all right so let's move on to our second example here so our second example looks at nitrogen and iodine so we're going to have one nitrogen and again no mono for the first element so i'm just going to put nitrogen and we don't change the ending here that's only on the second element and then this is going to be three which on our chart does monodi so this would be nitrogen tri iodide now it looks like this is spelled a little funny but we're going to keep these two eyes left a little cheat sheet for you down here for double vowels so if we see an ooh or an ao we're going to drop the first of the two vowels we're going to keep both vowels if we see io as in dioxide or if we see i i as in nitrogen tri iodide now let's move to this last one here we'll see where this rule comes in now i've got two nitrogens in this last example just like in carbon dioxide here we're going to have dye for two nitrogen for two nitrogens we're gonna end the name i ran out of space here so i'm gonna slip below here we're gonna have mono for one but we're not going to have mono oxide try to pronounce that you get monoxide it sounds almost with a little canadian flare to it we drop the first of the o's so what we get is dinitrogen monoxide not dinitrogen monoxide all right a different kind of compound you're going to see a lot in biology engineering health science classes that are coming up are acids so acids are going to typically have a hydrogen out front paired with non-metals or paired with polyatomics so here we're going to classify acids in two different uh subsets we're going to have binary acids which are only made of two elements and guess what hydrogen gonna be involved so it's gonna be hydrogen paired with typically a non-metal or we're going to have oxyacids which contain oxygen typically this is where you look at your polyatomic showing up so we're going to get into a couple examples of each so binary acids we said were made up of two elements that's where that binary term comes from it's going to come with an h because we said acids just a general form are going to have h out front a generic way to write acids is just h a because it's h paired with something h paired with an anion because the h itself shows up as a positive so we're going to name these by putting hydro out front this hydro is a prefix so when i have a binary acid this is going to be hydro as a prefix the base name of the non-metal here that's chlorine but we're going to make chlorine chlor plus ick and then end with acid so this is hydrochloric acid here i've got h paired with br so this is a binary acid two elements i'm going to start with a prefix hydro br is bromine so instead of caloric we're going to have bromine and then you end with acid here it's a little confusing on this one because we're not looking at something that falls in the normal scheme when we drop and end with ick so let's start this out like we have our previous examples we're gonna have a little twist though we're gonna start with hydro and then we're going to go with sulfur and then we're going to end with acid now the twist here is for h2s we're going to call this hydrosulfur ick acid we're not going to abbreviate it as hydrosulfic acid like we would have done uh when we were talking about sulfides we're keeping the full name and the acid there so this is just a common exception that you're going to run across but i won't try to catch on on exceptions when it comes to exam time okay so let's name our oxyanion so our oxyanions remember we said this is where you start to see polyatomic show up we're no longer in binary acids there were just two elements here we're going to have two little name twists if we have a polyatomic ion that ends in ite we're going to end in us acid if we have a polyatomic ion that ends in ate that's going to end in ick acid so two different ways this can go so way number one way number two we'll do some examples of rap number one first so clo2 if we look it up on our list this polyatomic is called chlorite so for these names we don't start with the hydro prefix for oxyacids we would just say chlorite and we drop the ite ending and instead we would go with ous acid so this would be chloros acid for hno2 this is nitrate but we're going to drop the ite ending just like we did up here we're going to go with nitrous acid now we said type 2 was where we had polyatomic ions that end with ate so in this example we can tell it's an acid again because there are h's out front but this has nitrate we'd know from our list of polyatomics and this is phosphate so in each of these we're going to take the base name of the oxyanion so the base name of our polyatomic and we're going to end instead we're going to drop the eights and end with ick acid so this nitrate becomes nitric acid now this is another odd case just like we had with sulfur not making hydrosulfur or hydrosulfic acid and made sulfuric acid instead this is going to make phosphoric acid just a common name for a very common acid that you're going to be using if we were using a systematic name here we would be calling it phosphic phosphatic acid okay now for naming though h3po4 phosphoric acid all right so table of common names when it comes to acids that contain polyatomic ions these oxyacids you can see that nitrite the it became us it gave us nitrous acid when we had clo2 chlorite gave us chlorus acid chlorate ates went to ick so chlorate became chloric acid acetate became acetic acid table vinegar so the take home here if you see an eight at the end of the polyatomic ion change the ending to ick acid if you see an ite change it to us acid for the ending okay now this looks ridiculous to start with but take a step back we're going to absorb it this is going to be all the naming that we just covered we have ionic naming this is when we have a metal and a non-metal we also said uh polyatomic show up in these we had these split into two categories this was type one this was invariant where the charge of the metal doesn't change these were dependable we had type 2 these are variant this is where our metal ion charge changed so these were transition metals and we had a pattern to name each of these types our variant used roman numerals to name those ionic compounds but most importantly no prefixes for ionic naming now over here from molecular naming we used prefixes we had mono uh and worked its way up mono die tried tetra and so on we had to memorize those prefixes and we looked at using the prefix with the first element prefix with the second element element and ending in ide remember the exception no prefix if we only have one of our first element like co2 was not mono carbon dioxide it was just carbon dioxide moving on we named our acids we had two categories we had binary acids just two elements like hydrochloric acid that's where we use hydro for our binary acids for oxyacids those were where we saw polyatomic show up and we had it goes to us acid and eight goes to ick acid so this is going to take some practice but really it's about putting pen to paper and learning a new language uh treat it like that you're gonna have to immerse yourself jump in and work some practice problems okay so let's break down each of these just to see where they might fall on how to use this floor check so co i've got a molecular compound why because co is just nonmetals so i'm going to end up using prefixes in this molecular naming caf2 this is a metal plus a non-metal how do we know that because on the periodic table f shows up over here nonmetals and ca shows up over here in the metals so we have a combination there so this is ionic our metal is in group two so this is a type one because i've got an invariant charge a dependable charge that's what it's saying by one type of ion so i didn't have to use the roman numerals because i'm looking at a formula with a metal it's very dependable now let's look at hf hf has an h out front that's clueing me in that it's an acid it's got f paired with it so it's just two elements so it's binary so that's why i'm going to use the hydro prefix and name it as a binary acid feno3 i've got an ionic compound because i have a metal paired with a polyatomic ion fe shows up in the transition metals so i've got a variant or type ii ionic compound that iron can form multiple charges because it shows up here in the transition metals so that's why you see these roman numerals show up when i look at these last two here i've got h out front that clues me into acid i've got polyatomics or oxyacids so there i'm going to go with one of two rules either my eight or my height deciding how i use the ending for the acids either ick acid or us acid okay so moral of the story take some time work some practice on naming really immerse yourself because it's going to take some practice okay we're going to wrap up by looking at formulas with a little bit of math but this is really important math that's going to show up a lot later in the course okay so let's start talking about formula mass so we're literally going to calculate the mass of the formula unit or the molecule what our formula is going to represent so what we do is for however many elements we have showing up i'll take the number of atoms of the first element times the mass we get off the periodic table plus the number of atoms in the second element times its mass and then for however many atoms i have i'm going to keep going or excuse me for however many elements i have i'll keep going so if i were to work it out for h2o we have got number of atoms of first element so two h's times the mass of h which is 1.008 and these are amu's plus the number of atoms of the second element so i have no number here so i'm just going to assume it's one one oxygen at 15.999 and let's see what we get here all right i get 18 when i add all this up 18.01 amu's for my formula mass for water representing the mass of just a single atom of water excuse me a single molecule of water a group of atoms so let's try something a little more difficult we're going to work our way through calcium phosphate uh we have got three elements here we have calcium we have phosphorus and we have oxygen we're going to take these one at a time so for the formula mass i'm going to take the first element it's calcium and i have three calciums we're going to multiply that by the atomic mass of calcium what's the atomic mass of calcium 40.078 we're going to add that to the number of phosphorus that i have so since i have this subscript outside of the parentheses that tells me that i have two of these phosphates so that means i have two times one or two phosphorous atoms what's the atomic mass of phosphorus 30.974 plus my last element was oxygen the two is outside the parentheses two times four gives me eight so this would be eight atoms of oxygen times 15.999 now we can figure out all these three terms and add them together and sorry i left out my units here these are masses off the table amu's we're talking about the individual formula unit here for the formula mass and we get and we get 310 oops 310 we get my pin back here 0.174 amu's and again we're taking for each element the number of each element that we have we're multiplying by the mass that we get off the periodic table for example calcium when we look it up we would see this 40.078 for the average atomic mass for phosphorus we had two the mass of each phosphorus from the table we had eight oxygens the mass of each oxygen from the table we multiply and then add it all up giving us our formula units mass or formula mass all right thank you for joining me for chapter five make sure you take your time with this one this is a very foundational chapter very important to the rest of the course all right have a good one