in this video we're going to focus on naming ionic compounds this is going to be binary ionic compounds those with polyatomic ions and those with transition models where you have to incorporate the Roman numerals so let's begin let's start with the basics how can we write the name of NAC so if we're given a chemical formula how can we write the name of this compound so it's an ionic compound and ionic compounds are composed of a metal and a non-metal you need to distinguish it from molecular compounds because the naming system is different for molecular compounds typically not all the time but most of the time you it's consisting of two non-metals and you have to use rules like monoi Tri Tetra and things like that but when you have an ionic compound you don't need to use the prefixes mono di Tri Tetra so keep that in mind so what you need to do is name the first element na is called sodium now the second element instead of calling it chlorine you're going to add the end in chloride so it's called sodium chloride let's try another example so let's say if we want to write the name of mgbr2 so first use the periodic table to identify mg mg is called magnesium and then you look at the second element on a periodic table was called bromine but instead of saying bromine we're going to add the suffix ID so it's going to be bromide so to name it it's simply called magnesium bromide let's try some more examples alf3 and CAO so Al stands for aluminum F represents Florine but we're going to say fluoride so alf3 is called a aluminum fluide now what about CAO what is the name for that CA stands for calcium and the O represents oxygen but we're going to say oxide so this is called calcium oxide now let's try two more examples write the chemical names of sr3 N2 and b s so Sr stands for strontium n represents nitrogen so this is going to be called strontium nitride now what about the last one b s ba is associated with the element barium s is sulfur but we're going to change it to sulfide so barium sulfide so that's how you can name binary ionic compounds now sometimes you might be given an ionic compound that contains a polyatomic ion and the periodic table won't help you much in this case at least for the polyatomic ion you simply have to commit it to memory if you're fortunate your teacher is going to give you the polyatomic ion sheet and so you could just use that look it up if not you have to commit it to memory so you're going to need it for the rest of your Chemistry course I devise you just to memorize it and it's just going to make life easier so let's start with li2 so4 and na2 CO3 so how can we name this substance Li you could look that up in the periodic table that's a lithium now so4 is a polyatomic ion it has a single name the periodic table won't help you with that you need to look it up in your polyatomic ion sheet so4 is simp simply called sulfate and that is something you just have to know now there's a video in which I made that goes over the common polyatomic ions that you need to look for just look it up on YouTube you should be able to find it and it's just it'll help you to like understand how to name certain polyatomic ions so it's easier for you to memorize it it helps you to get a better understanding of the naming system na2 CO3 na represents sodium CO3 is called carbonate so combined it's sodium carbonate here's another one name this one B aoh2 and K C2 h32 or just O2 ba is barium and O when you see it it's known as hydroxide so this is going to be called barium hydroxide now what about the next example what does k stand for K is called potassium and C2 h302 that's a single polyatomic ion known as acetate so combined this is potassium acetate now I'm going to give you two more examples with polyatomic ions go ahead and name this one and also nh4 NO3 Zan stands for zinc cl4 is known as per chlorate so collectively this is zinc per chlorine now the last one it's ionic compound even though it doesn't have a metal inside of it nh4 that's known as ammonium that's a polyatomic ion NO3 is another polyatomic ion which is called nitrate so combined this is ammonium nitrate consider these two compounds fecl2 and fe3 how can we name these two compounds Fe stands for iron and cl is going to be chloride instead of chlorine but now how is this going to be different from the other one because the other one's also iron chloride so we need a way to distinguish fe2 from fe3 it turns out that certain transition metals have multiple charges and so you need to use Roman numerals to specify the charge of the transition metal there are certain metals that are not transition metals that also have multiple charges and you would still use the ran numeral system for it so what we need to do is figure out the charge of Fe and F2 now the charge of a single chloride ion is NE 1 and in this example there are two of them so the total negative charge is -2 therefore Fe has to have a positive two charge to neutralize the negative2 charge from the two chloride ions so therefore since the charge in Fe is positive2 this is called iron 2 chloride now in the next example we have three chloride ions so the total charge is NE 3 which means the total charge on Fe has to be positive 3 the net charge has to add up to zero because there's no charge on F3 so therefore this is going to be called iron 3 chloride and that's how you can name ionic compounds that have Metals with variable charges let's look at another example cubr and cubr2 go ahead and name these two compounds now let's start with cubr bromide has a negative one charge and there only one of them so copper has to balance that negative one charge so it must have a plus one charge so therefore this is going to be called copper one bromide because it has a plus one charge now what about the second example what's the name for it well in this case we have two bromide ions so the total charge is -2 so therefore copper has to have a plus two charge to balance the two negative charges so it's going to be copper to bromide now what about CRS and CR2 S3 go ahead and try those two examples so let's find the charge on sulfur sulfur has a NE -2 charge which means in this example chromium has to have a plus two charge so this is going to be called chromium 2 sulfide now for the second example there's three sulfide ions so the total negative charge is6 which means the total positive charge has to be positive six now there's two chromium ions so for the total charge to add up to plus six each of these chromium ions have to have a plus three charge so therefore this is going to be called chromium 3 sulfide so hopefully these examples are helping you to get a good idea of how to name these types of ionic compounds try this SN and SN O2 oxygen has a minus two charge so tin has to have a plus two charge so the first one is called 10 2 oxide now let's move on to our next example so this time there's two oxide ions with a total negative charge of4 but there's only one 10 atom so therefore it has to have a plus4 charge so this is going to be called 10 4 oxide now for those of you who need to review the Roman numeral system here's some Basics this is one this is two this represents three now this is five now if you put the I symbol to the left of the five it really means subtraction like 5 minus one so this is four if you put it to the right of the five it means addition five + 1 is six so if you want to write seven put two i's to the right of the V so that represents seven so just a basic tutorial of Roman numerals in the course of this class you don't really need to go past seven I haven't seen any examples beyond that so if you know these numbers you should be good now let's try this one PB so4 and PB co32 so4 is sulfate and it has a negative -2 charge which means PB has to have a positive two charge so this is going to be called lead two sulfate now for the last example carbonate has a minus two charge but there's two carbonate ions in that compound so the total negative charge is4 and there only one PB atom so it has to Bear the entire positive four charge so this is going to be called lead for carbonate and that is it for this video so now you know how to name ionic compounds