Mg liberates `H_(2)` on reaction with

Options

A. dil. HCl
B. dil. `H_(2)SO_(4)`
C. very dil. `HNO_(3)`
D. All of these

Answer

To solve the question regarding which substances magnesium (Mg) liberates hydrogen gas (H₂) when it reacts with them, we will analyze the reactions of magnesium with the given acids: dilute hydrochloric acid (HCl), dilute sulfuric acid (H₂SO₄), and dilute nitric acid (HNO₃).

### Step-by-Step Solution:

1. **Identify the Reactants**: We need to consider the reactions of magnesium with the following acids:
- Dilute Hydrochloric Acid (HCl)
- Dilute Sulfuric Acid (H₂SO₄)
- Dilute Nitric Acid (HNO₃)

2. **Reaction with Dilute Hydrochloric Acid (HCl)**:
- The reaction can be written as:
\[ \text{Mg} + 2\text{HCl} \rightarrow \text{MgCl}_2 + \text{H}_2 \]
- Here, magnesium reacts with hydrochloric acid to produce magnesium chloride and hydrogen gas.

3. **Reaction with Dilute Sulfuric Acid (H₂SO₄)**:
- The reaction can be written as:
\[ \text{Mg} + \text{H}_2\text{SO}_4 \rightarrow \text{MgSO}_4 + \text{H}_2 \]
- In this case, magnesium reacts with sulfuric acid to yield magnesium sulfate and hydrogen gas.

4. **Reaction with Dilute Nitric Acid (HNO₃)**:
- The reaction can be written as:
\[ \text{Mg} + 2\text{HNO}_3 \rightarrow \text{Mg(NO}_3)_2 + \text{H}_2 \]
- Here, magnesium reacts with nitric acid to form magnesium nitrate and hydrogen gas.

5. **Conclusion**: From the above reactions, we can see that magnesium liberates hydrogen gas when it reacts with all three acids: dilute HCl, dilute H₂SO₄, and dilute HNO₃. Therefore, the correct answer is:
- **Option D: All of these**