Hydrogen is usually prepared in the laboratory by the action of dilute sulphuric acid on granulated ____ .

Explanation

To solve the question, we need to identify the substance that reacts with dilute sulfuric acid to produce hydrogen gas in the laboratory. Here’s a step-by-step solution:

### Step-by-Step Solution:

1. **Understanding the Reaction**:
- Hydrogen gas can be produced by the reaction of an acid with a metal. In this case, we are dealing with dilute sulfuric acid (H₂SO₄).

2. **Identifying the Metal**:
...