# How do you balance O_2 + H_2S -> H_2O + S?

Apr 18, 2016

This is a double displacement reaction. It can be balanced by ensuring that there are the same number of molecules on both sides.

#### Explanation:

First of all, we are going to need at least two molecules of oxygen on the right side. This means we will end up with 4 molecules of hydrogen, which gives us the following:

${O}_{2} + {H}_{2} S \to 2 {H}_{2} O + S$

Since we have four molecules of hydrogen on the right side, we need four molecules of hydrogen on the left as well:

${O}_{2} + 2 {H}_{2} S \to 2 {H}_{2} O + S$

Seeing that we have four molecules of hydrogen on the left, we have two molecules of sulphur on the left as well.

${O}_{2} + 2 {H}_{2} S \to 2 {H}_{2} O + 2 S$

This is totally balanced, since there is the same amount of everything on the left and right sides.

Hopefully this helps!