# Chemical Forums

## Chemistry Forums for Students => High School Chemistry Forum => Topic started by: al220007 on November 22, 2022, 04:47:37 PM

Title: Calculate the oxidation state of Cr(ClO3)3 and others
Post by: al220007 on November 22, 2022, 04:47:37 PM
I was calculating some oxidation states but I couldn't solve 3 of the compounds my teacher gave:
• Cr(ClO3)3
• ZnSO4
• Al2(SO4)3

I know O has oxidation state equals -2 in all of them and Cl on the first compound hasn't oxidation state equals -1 because it's bonded with an O but now I'm stuck.

How should I solve them? Is there any rule I'm missing?

Title: Re: Calculate the oxidation state of Cr(ClO3)3 and others
Post by: Borek on November 22, 2022, 05:26:34 PM
Would writing these compound dissociated to ions help?
Title: Re: Calculate the oxidation state of Cr(ClO3)3 and others
Post by: Orcio_87 on November 22, 2022, 06:04:05 PM
Quote
I know O has oxidation state equals -2 in all of them and Cl on the first compound hasn't oxidation state equals -1 because it's bonded with an O but now I'm stuck.
In neutral compound (not cation or anion) sum of the all oxidations states is equal 0.

Cr(ClO3)3 is a salt, it dissociate to cation and anion.
Title: Re: Calculate the oxidation state of Cr(ClO3)3 and others
Post by: al220007 on November 22, 2022, 06:41:04 PM
Would writing these compound dissociated to ions help?

I hope I did it right:

• Cr(ClO3)3 --> Cr3+ + 3ClO3-
• ZnSO4 --> Zn2+ + SO42-
• Al2(SO4)3 --> 2Al3+ + 3SO42-

Now I calculated the oxidation state of each one separatedly and I think the result it's correct!

Example with Cr(ClO3)3

 3 + 3(5 + 3(-2)) = 0 | +3 = 3 | +5 - 2 = -1 Cr(ClO3)3 | Cr3+ | 3ClO3-

I just need to review the ions charges.

Thank you <3
Title: Re: Calculate the oxidation state of Cr(ClO3)3 and others
Post by: Hunter2 on November 23, 2022, 12:10:19 PM
Looks OK.