`0.116 g` of `C_(4)H_(4)O_(4) (A)` in neutralised by `0.074 g` of `Ca(OH)_(2)`. Hence protonic hydrogen `(H^(o+))` in `(A)` will be

Options

A. 1
B. 2
C. 3
D. 4

Explanation

To solve the problem, we need to determine the number of protonic hydrogens (H⁺ ions) in the compound \( C_4H_4O_4 \) (A) that are neutralized by the given amount of \( Ca(OH)_2 \).

### Step-by-Step Solution:

1. **Calculate the Molar Mass of \( C_4H_4O_4 \)**:
- The molecular formula \( C_4H_4O_4 \) consists of:
- Carbon (C): 12.01 g/mol × 4 = 48.04 g/mol
- Hydrogen (H): 1.008 g/mol × 4 = 4.032 g/mol
- Oxygen (O): 16.00 g/mol × 4 = 64.00 g/mol
- Total molar mass = 48.04 + 4.032 + 64.00 = 116.072 g/mol (approximately 116 g/mol).

2. **Calculate the Number of Moles of \( C_4H_4O_4 \)**:
- Given mass of \( C_4H_4O_4 \) = 0.116 g.
- Moles of \( C_4H_4O_4 \) = \(\frac{\text{mass}}{\text{molar mass}} = \frac{0.116 \text{ g}}{116 \text{ g/mol}} = 0.001 \text{ mol}\).

3. **Calculate the Molar Mass of \( Ca(OH)_2 \)**:
- The molecular formula \( Ca(OH)_2 \) consists of:
- Calcium (Ca): 40.08 g/mol
- Oxygen (O): 16.00 g/mol × 2 = 32.00 g/mol
- Hydrogen (H): 1.008 g/mol × 2 = 2.016 g/mol
- Total molar mass = 40.08 + 32.00 + 2.016 = 74.096 g/mol (approximately 74 g/mol).

4. **Calculate the Number of Moles of \( Ca(OH)_2 \)**:
- Given mass of \( Ca(OH)_2 \) = 0.074 g.
- Moles of \( Ca(OH)_2 \) = \(\frac{0.074 \text{ g}}{74 \text{ g/mol}} = 0.001 \text{ mol}\).

5. **Determine the Number of Moles of \( OH^- \)**:
- Each mole of \( Ca(OH)_2 \) produces 2 moles of \( OH^- \).
- Therefore, moles of \( OH^- \) = \( 0.001 \text{ mol} \times 2 = 0.002 \text{ mol}\).

6. **Determine the Number of Moles of Protonic Hydrogens (H⁺)**:
- In a neutralization reaction, the moles of \( H^+ \) will equal the moles of \( OH^- \) that react.
- Thus, moles of \( H^+ \) = moles of \( OH^- \) = 0.002 mol.

7. **Calculate the Number of Protonic Hydrogens in \( C_4H_4O_4 \)**:
- Since we have 0.001 moles of \( C_4H_4O_4 \) and it neutralizes 0.002 moles of \( OH^- \), it indicates that there are 2 moles of \( H^+ \) per mole of \( C_4H_4O_4 \).
- Therefore, the number of protonic hydrogens in \( C_4H_4O_4 \) is 2.

### Final Answer:
The number of protonic hydrogens \( (H^+) \) in \( C_4H_4O_4 \) is **2**.