Give reason for the following:
Concentrated sulphuric acid is not used in the laboratory preparation of hydrogen.

Explanation

**Step-by-Step Text Solution:**

1. **Understanding the Reaction**: In the laboratory preparation of hydrogen gas, zinc is typically reacted with sulfuric acid. The type of sulfuric acid used can affect the products of the reaction.

2. **Using Dilute Sulfuric Acid**: When zinc granules react with dilute sulfuric acid, the reaction produces zinc sulfate and hydrogen gas:
\[ \text{Zn} + \text{H}_2\text{SO}_4 \text{(dilute)} \rightarrow \text{ZnSO}_4 + \text{H}_2 \uparrow \]
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