# Oxidation of sulfide to sulfate

1. Jun 4, 2015

### namata99

Hello, I would need with this task:

Write a balanced equation for the oxidation of dissolved H2S to sulfate by dissolved oxygen. Indicate the oxidation states of the redox-sensitive elements involved.

- For each redox couple, write the oxidized and reduced species in an equation and balance the amount of element, except H and O.
- Balance electroneutrality by adding electrons.
- Balance the number of oxygen atoms by adding H2O.
- Balance the number of protons (H) by adding H+.
- Subtract the two half-reactions, canceling electrons to obtain the complete redox reaction.

Sulfide to Sulfate: H2S ->SO4 2-

Im not sure which are the redox couples and where to add electrons, but Ive got this so far:

H2S + 1/2O2 -> S0 + H2O
S0 + 1 1/2O2 + H2O -> SO4 2- + 2H+

Can someone provide his advice or comment if this is correct and how to proceed further? Thanks!

2. Jun 4, 2015

### Staff: Mentor

Why two steps oxidation and not a single step?

What is getting reduced?