now this will be the second part of our two-part series of the end of chapter 2 where we're looking at chemical nomenclature now in this video we're gonna look at how we need in compounds that contain polyatomic ions and we're gonna look at how we name acids so first let's look at polyatomics now polyatomic ions are covalently bonded atoms that together have an overall ionic charge so it's a bunch of nonmetals that are bonded together in using covalent bonds however together they all hold on to a negative charge now if we want a full list of all of the polyatomic ions I say all of them there's actually more than those in the list but if we want a full list for this course there's they are listed in table 2.3 however you are only responsible for memorizing the following polyatomic ions for example you are responsible for knowing the following polyatomic ions you need to know their name you need to know their formula and you need to know their charge so that list is acetate which can be written one of two ways either a ch3coo minus or C 2 H 3 o 2 minus you need to know carbonate Co 3 with a 2 minus charge bicarbonate hco3 and with a minus charge cyanide should see in minus hypochlorite which is co o minus chlorite which is CLO 2 minus chlorate which is CLO 3 minus perchlorate which is CLO 4 with a minus charge ammonium which is NH 4 with a bus trip plus charge and this is my only positively charged polyatomic ion nitrite which is no.2 with a minus charge nitrate which is no.3 with a minus charge hydroxide which is Oh H where the minus charge phosphite which is po3 with a minus 3 charge phosphate which is po4 with a 3 minus charge sulfite which is so3 with a 2 minus charge and sulfate which is so4 where the 2 minus charge now I think the best way to memorize these is either to make flashcards or to make a Quizlet and in fact if you search Quizlet there have been numerous students who have made memorization tables for the polyatomic ions before it is absolutely critical for your well being in the later part of this course and also especially if you have to take chem 102 it is very important that you get these things memorized now also it'll show up in biology courses and it may show up in other science courses so it doesn't hurt to have these memorize hey you're just increasing the knowledge in your brain so how do we name things that have polyatomic ions well thankfully because you've got to memorize all those polyatomic ions the naming part for the compounds with polyatomic ions is actually really easy that's the easiest of the nomenclature series because all compounds that include polyatomic ions are ionic compounds so if I want to name a compound I'm going to use the ionic rules and all I have to do is know the names of my polyatomic ions so let's say I had nh4cl well I look at this formula I see that I have an NH for which I know is the ammonium group so nh4cl is ammonium chloride okay ba o h2 well I see the Oh H I know that's my polyatomic ion hydroxide so this becomes barium hydroxide all right PB no3 - all right I see no.3 I recognize that this is the nitrate ion so this is lead with two nitrates now as we discussed in the previous video lead is one of my elements that I have to identify what the charge is well nitrate has a minus one charge I have two nitrates which gives me a minus 2 charge the lead must provide enough positive charge to cancel out the minus 2 from the two nitrates so I must be looking at lead ii nitrate going in Reverse let's say i have the name and i want to find the cop the formula magnesium carbonate that is mg now mg is in the second column so that is mg 2 plus because it's a main group element carbonate co 3 2 minus and if I do my crisscross then I would be mg 2 Co 3 2 let's since these are ionic compounds I need the lowest whole number ratio so that's just cancelling each other out that's mg Co 3 ammonium sulfide I know ammonium nh4+ with a plus charge sulphide is from sulfur which is a group 16 element which means it's a 2 - doing my crisscross means I need to ammonium and one sulfur so that's NH 4 with a 2 sulfur iron 3 chlorate well this 3 tells me that's Fe with a 3 plus chlorate a clo3 - I do my crisscross that tells me I need 3 chlorates and 1 iron so that's Fe CLO 3 3 now the final part in this video we're gonna look at acid nomenclature now acids are going to be covered in more detail in chapter 4 and we're really going to look at them very heavily in kim 102 so we're going to come back to this concept a couple different times but for right now we're just going to recognize that acids our chemicals which donate or give away HP they give away H+ ions now for this reason acid formulas tend to begun with H so for example HCl h2 so4 HC to h3o - all three of these are acids and I have a hint that they're acids because the formula is starting with an H now naming acids follows three rules and they're all based on the anion and the chemical formula so the second part and the point formula after that H so my three rules are anions that end with IDE become hydro blank Nick acids anion set end with ite become blank o us acids and anions at end with a te become blank ik acids so these are the three rules based on the suffix on the anion in hell I'm going to name assets so let's look at this in practice its name the following acids h2s have an H at the front which means I could be looking at an acid if I were to name this by its molecular name this would be die hydrogen sulfide to turn it into an acid I'm going to take the anion switch the suffix from and I switch the suffix since its IDE that's going to become hydro sulfuric acid and again that's because I have the suffix IDE I put a hydro in front and then I switch the suffix from IDE to I see it hclo4 okay I have an H in front I'm looking at an acid the molecular name would be hydrogen perchlorate now that 8ee on the perchlorate the a te has become a bit going to become an ik so this becomes perchloric acid h2so4 the sulfite polyatomic ion that ite is going to become an O you s and so this is going to become sulfuric acid and that's why we name acids that's to finish of this video