all right class let's go over these polyatomic ions there's a few rules you can use to make your life a little bit easier let's start off with notice that all of these polyatomic ions are anions except for this one okay ammonium ammonium is the only cation and it's an important one so you want to know that ammonium is a cation we're going to see that quite a bit the rest of them are anions so all these polyatomic ions are anions and how can we uh you know try to keep track let's look at all the eights first why don't you memorize all the a's there's sulfate [Music] chlorate [Music] nitrate okay let's start with those first you want to know all of those and no phosphate also let's try a few quick rules that'll help you learn the aids so if you know the eights so if you know the green ones so if you know the eights the heights have the same charge but one less oxygen chlorate is cl chlorine with three oxygens with a minus charge chlorite is the same charge with one less oxygen sulfite sulfate you want to know has is sulfur with four oxygens so4 and a two minus charge sulfite is so32 minus okay nitrate no3 minus nitrite no2 minus all right that gets you a few things there the other rule here is that hypo means one further to the ite so if chlorate with clo3 minus it with clo2 minus you get rid of one more oxygen now it's hypo light hypochlorite okay chlorate again chlorate to clo3 minus perchlorate means add an extra oxygen so clo4 minus and if you remember perchlorate a clo4 minus permanganate has manganese instead of chlorine but perchlorate to clo4 minus permanganate manganese is mn mno4 minus all right so going from eight you can get to the i it's the hypos and the pers now if you know the eights if you say sulfate so4 two minus if you say bisulfate it's the same as adding an h plus to the sulfate so you add in a hydrogen and you make the charge go one more positive so we get hso4 with a one minus that's hydrogen sulfate or bisulfate we see the same thing with uh sulfite universe sulfite from sulfate bisulfite or hydrogen sulfite is an add an h to sulfite hso3 minus and the same thing with phosphate phosphate po43 minus hydrogen phosphate you got a hydrogen the charge goes down up by one so hpo4 two minus dihydrogen phosphate you had two h pluses so we get h2 po4 minus all right um you should know carbonate so let's go back here to carbonate again carbonate if you know carbonate bicarbonate or hydrogen carbonate carbonate is co32 minus bicarbonate is hco3 minus all right that gets you all those yellow ones are connected to the green ones so if you know the green ones you can kind of think your way through the other ones and then the rest of them you do have to learn let's pick a different color hey purple so you want to know acetate hydroxide chromate and dichromate uh they're not the most important ones but chromate and dichromate chromate again looks like permanganate or perchlorate dichromate it looks a little bit strange you won't see that very often in class you do see it in the lab the other ones we have cyanide cn minus and then peroxide o2 two minus so if you know the green ones hopefully you can get to the yellow ones with a little bit of thinking and then you wanna know the purple ones and then just because it i will always write acetate acetate they write is c2 h3o2 minus i don't like that structure that formula because it doesn't really talk about the structure so when i write acetate i write ch3 co2 minus because that's just what the structure looks like you have a hydrogen connected to the carbon connected to a carbon and that's what it looks like so i like ch3 co2 minus for acetate either one of those formulas is accurate i like the one that's more structurally correct all right and then there's ammonium nh4 plus if you remember ammonia ammonia is nh3 nh3 if you add an h plus to it you get ammonium the cation nh4 plus all right so hopefully that's a little a few little tricks to help you memorize these definitely work on this table you'll need it next week and that's it for the night hope you're staying safe and trying to keep cool right goodnight