When hydrogen sulfide reacts with oxygen, water and sulfur dioxide are produced. The balanced equation for this reaction is:

2H2S + 3O2 → 2SO2 + 2H2O

Explanation:

Step 1: Data given

Hydrogen sulfide = H2S

Oxygen = O2

sulfur dioxide = SO2

water = H2O

Step 2: The unbalanced equation

H2S + O2 → SO2 + H2O

Step 3: Balancing the equation

H2S + O2 → SO2 + H2O

On the left side we have 2x O (in O2) and on the right side we have 3x O (2x in SO2 and 1x in H2O). To balance the amount of O, we have to multiply O2 (on the left side) by 3 and SO2 and H2O on the right side by 3.

H2S + 3O2 → 2SO2 + 2H2O

On the right side we have 4x H and on the left side we have 2x H. To balance the amount of H, we have to multiply H2S by 2.

Now the equation is balanced.

2H2S + 3O2 → 2SO2 + 2H2O