Hydrogen is not prepared by the reaction of concentrated sulphuric acid on zinc. Explain.

Explanation

To explain why hydrogen is not prepared by the reaction of concentrated sulfuric acid on zinc, we can break down the process step by step:

### Step 1: Understanding the Reactants
- **Concentrated Sulfuric Acid (H₂SO₄)**: This is a strong acid that can react with metals.
- **Zinc (Zn)**: A reactive metal that can displace hydrogen from acids.

### Step 2: Expected Reaction
When zinc reacts with sulfuric acid, we would typically expect the following reaction:
...