What Happens When Magnesium Sulfide Reacts With Water?

When magnesium sulfide (MgS) reacts with water (H2O), it undergoes hydrolysis to produce magnesium hydroxide (Mg(OH)2) and hydrogen sulfide (H2S) gas. The incomplete reaction can be represented by the following chemical equation:

MgS + H2O → Mg(OH)2 + H2S

The hydrogen sulfide gas that is produced has a strong odor of rotten eggs and is highly toxic. Magnesium hydroxide, on the other hand, is a white precipitate that is insoluble in water. In summary, when magnesium sulfide reacts with water, it produces magnesium hydroxide and hydrogen sulfide gas.