Hydrogen from `HCl` can be prepared by

Options

A. Cu
B. P
C. Mg
D. Hg

Answer

To prepare hydrogen from hydrochloric acid (HCl), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reaction**: We need to find a suitable metal that can react with hydrochloric acid (HCl) to produce hydrogen gas (H2).

2. **Select the Metal**: Among the metals, we know that alkali and alkaline earth metals are capable of releasing hydrogen when they react with acids.

3. **Choose the Correct Metal**: From the options provided, we identify magnesium (Mg) as an alkaline earth metal.

4. **Write the Chemical Reaction**: The reaction of magnesium with hydrochloric acid can be represented as:
\[ \text{Mg} + 2 \text{HCl} \rightarrow \text{MgCl}_2 + \text{H}_2 \]
Here, magnesium reacts with hydrochloric acid to form magnesium chloride (MgCl2) and hydrogen gas (H2).

5. **Conclusion**: Therefore, the correct answer is magnesium (Mg), as it is the metal that can react with HCl to produce hydrogen.

### Final Answer:
Hydrogen from HCl can be prepared by reacting it with magnesium (Mg).

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