What weight of oxalic acid `(H_(2)C_(2)O_(4).2H_(2)O)` is required to prepare `1000mL` of `N//10`solution?

Options

A. `9.0g`
B. `12.6g`
C. `6.3g`
D. `4.5g`

Explanation

To find the weight of oxalic acid (H₂C₂O₄·2H₂O) required to prepare 1000 mL of a N/10 solution, we can follow these steps:

### Step 1: Determine the Normality and Volume
- Given:
- Normality (N) = 1/10
- Volume (V) = 1000 mL = 1 L (since 1000 mL = 1 L)

### Step 2: Calculate the Equivalent Weight of Oxalic Acid
- The molecular formula of oxalic acid dihydrate is H₂C₂O₄·2H₂O.
- To find the molecular mass:
- H: 1 × 2 = 2
- C: 12 × 2 = 24
- O: 16 × 4 = 64
- H₂O: 18 × 2 = 36
- Total molecular mass = 2 + 24 + 64 + 36 = 126 g/mol

- The n-factor of oxalic acid (H₂C₂O₄) is 2 because it can donate 2 protons (H⁺ ions) in solution.

### Step 3: Calculate the Equivalent Mass
- Equivalent mass = Molecular mass / n-factor
- Equivalent mass = 126 g/mol / 2 = 63 g/equiv

### Step 4: Use the Normality Formula
- The formula for normality is:
\[ N = \frac{\text{mass}}{\text{equivalent mass} \times \text{volume in liters}} \]
- Rearranging the formula for mass:
\[ \text{mass} = N \times \text{equivalent mass} \times \text{volume in liters} \]

### Step 5: Substitute the Values
- Substitute the values into the equation:
\[ \text{mass} = \left(\frac{1}{10}\right) \times 63 \, \text{g/equiv} \times 1 \, \text{L} \]
- Calculate the mass:
\[ \text{mass} = \frac{63}{10} = 6.3 \, \text{g} \]

### Conclusion
The weight of oxalic acid required to prepare 1000 mL of a N/10 solution is **6.3 g**.

---