00:01
So this video, we're gonna talk about question 80 from tractor to which says right the formula for each of the following compounds.
00:09
So when they were given chromium three hydroxide, so hydroxide is a poly atomic eye on that's just one oxygen atom and one hydrogen atom, and it has a negative charge of minus one charge.
00:22
Um, and we know that chromium in this case has a plus three charge because of the roman numeral three that's in parentheses.
00:31
So we know that we're gonna have c r and o h.
00:37
Um, so since our chromium has a plus three charge and our hydroxide has a minus one charge, we need three of the hydroxide in order to counter that positive charge.
00:49
So we're gonna put our wage in parentheses, and then we add a subscript of two, um, in part b, were given magnesium cyanide, so magnesium is mg and cyanide is a carbon and nitrogen atom on and sign in, takes a charge of minus one.
01:09
Um, so magnesium usually takes a charge of plus two.
01:15
Um, so in order to counter that we need two of our cyanide is to counter that positive charge and see we're given lead for carbonate so we know that our leads gonna have a plus for charge.
01:30
So we have pb with a plus four charge and then carbonate is ceo three with the minus to charge...