Question

Find oxidation number for the AuCl4 in HAuCl4

Is it +1 or -1?

Answer 1

it's 4+ in AuCl4, if you add a hydrogen, you're eliminating the need for a + charge on the Au atom. so it's 3+ in HAuCl4

Answer 2

wait were referring to gold?

Answer 3

were you*

Answer 4

No, it wanted the number for AuCl4.

How is AuCl4 4+?

Here is another...KMnO4. Find the Mn. Would it be +7?

Answer 5

we'll the overall charge on AuCl4 is zero (given that Au is 4+) because the charges cancel out.

yep, it is.

Answer 6

Thanks, I may need help on a few more sometime.

Answer 7

no problem, dude

Answer 8

How did you get Au as 4+.

Answer 9

Cl is -1, there is 4 of them. In order to balance that we need a 4+ charge

Answer 10

Thanks

Answer 11

Alright, so for H2SO4--find SO4

So H2 is 2+ and SO4 is -10? So -8 overall?

Answer 12

\(H_2SO_4\) is neutral, H is +1 theres are 2 of them. SO4 is 2- as a polyatomic ion. O is 2- there are 4 of them, S is therefore +6.

Answer 13

Forgot about that, thanks!

Na2BiO3, find BiO3
Na2 is +2, Bi is 3- and o3 is 6- so is it -7?

Answer 14

nope, you have to work with what you know, then compensate for the charges with the more labile elements.

Na is 2+, then you would do the oxygen, 2- (x3), so you're left with 4+.
Bi is then 4+

remember all these are neutral so the charges have to cancel out.

Answer 15

Right, but this wants the overall charge of the BiO3 in the Na2BiO3 compound. Does that mean BiO3 is 2-?

Answer 16

yes

Answer 17

Is Mg2P2O7, find P2O7, -4?

Answer 18

\(\checkmark\)

Answer 19

Alright, so H2C2O4, find C2O4.

Is it -2?

Answer 20

yes, are you sure it's C2O4 though?

not Cr2O4?

Answer 21

I thought the same, but no, it just says C2. Probably a typo from the professor.

Answer 22

seems like it.

Answer 23

NaBiO3, find Bi, is it +5?

Answer 24

yuup

Answer 25

It seems like a lot of them are -2.