How much zinc should be treated with excess of dilute hydrochloric acid to obtain 2.24 litres of hydrogen at S.T.P.

Explanation

To determine how much zinc should be treated with excess dilute hydrochloric acid to obtain 2.24 liters of hydrogen gas at standard temperature and pressure (S.T.P.), we can follow these steps:

### Step 1: Write the balanced chemical equation
The reaction between zinc (Zn) and hydrochloric acid (HCl) can be represented as:
\[ \text{Zn} + 2 \text{HCl} \rightarrow \text{ZnCl}_2 + \text{H}_2 \]

### Step 2: Determine the relationship between zinc and hydrogen
From the balanced equation, we see that:
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