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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: Mr. Raru on December 28, 2005, 09:36:44 PM

Title: Is it true that sulfide is oxidized to sulfate while H2S is oxidized to S8?
Post by: Mr. Raru on December 28, 2005, 09:36:44 PM
Is it true that sulfide is oxidized to sulfate while H2S is oxidized to S8? Why is this so when both have an oxidation number of 2 to begin with?
Title: Re: Is it true that sulfide is oxidized to sulfate while H2S is oxidized to S8?
Post by: Mitch on December 28, 2005, 09:38:12 PM
In what reaction?
Title: Re: Is it true that sulfide is oxidized to sulfate while H2S is oxidized to S8?
Post by: Mr. Raru on December 31, 2005, 12:11:09 PM
A solution of copper(II) sulfide is oxidized by dilute nitric acid.
Title: Re: Is it true that sulfide is oxidized to sulfate while H2S is oxidized to S8?
Post by: Alberto_Kravina on December 31, 2005, 12:33:33 PM
Hmmm...solution of copper sulfide? copper sulfide has apretty low solubility product (Ksp(CuS) = 1.3×10-3 6)
Sulfide is partially oxidized to sulfate with dil. nitric acid.

H2S is oxidized to S8 with oxygen:

8 H2S + 4 O2 ----> S8 + 8 H2O

Quote
Why is this so when both have an oxidation number of 2 to begin with?
I don't know if I understood the question, but I think that it depends on the strength of the oxidation agent.