Question

How to calculate oxidation number of chlorine in Al(ClO4)3

Answer 1

What is the overall charge of perchlorate?

Answer 2

I don't know?

Answer 3

the overall charge of perchlorate is -1

Answer 4

what about oxygen, what is the charge of it?

Answer 5

-2

Answer 6

Correct. How many oxygen atoms are there?

Answer 7

12

Answer 8

4 x 3=12 right

Answer 9

- 2 right or 7

Answer 10

3

Answer 11

Questions is what is the oxidation number of in Al(ClO4)3 ?

Answer 12

Correct. So Oxygen has 12 atoms and -2 charge
Chlorine has 3 atoms.
Al has a charge of +3 and it has only one atom
The overall charge of a compound has to equal to zero. That means, the information that we know can be applied as
\(+3+3\color{red}{x}+(-2)(12)=0\)
The x in red means that we don't know the charge of chlorine but we know it has 3 atoms.