What is the formula for hydrosulfuric acid?

The formula for hydrosulfuric acid is \( \text{H}_2\text{S} \).

### Explanation:

1. **Naming**: Hydrosulfuric acid is an aqueous solution of hydrogen sulfide (\( \text{H}_2\text{S} \)), which is a weak acid formed when hydrogen sulfide dissolves in water.

2. **Composition**:
- Each molecule of hydrosulfuric acid consists of two hydrogen atoms (H) and one sulfur atom (S).
- Therefore, the chemical formula is derived from the presence of these atoms in the compound.

3. **Acid Behavior**:
- In solution, \( \text{H}_2\text{S} \) can dissociate into hydrogen ions (\( \text{H}^+ \)) and sulfide ions (\( \text{S}^{2-} \)), which is what gives it acidic properties.

So, the correct formula for hydrosulfuric acid is \( \text{H}_2\text{S} \).