Equivalent weight of crystalline oxalic acid is

Options

A. (a)`30`
B. (b)`63`
C. (c)`53`
D. (d)`45`

Explanation

To find the equivalent weight of crystalline oxalic acid, we will follow these steps:

### Step 1: Identify the formula of crystalline oxalic acid
Crystalline oxalic acid is represented as \( C_2H_2O_4 \cdot 2H_2O \). This indicates that it consists of two molecules of water of crystallization.

### Step 2: Calculate the molecular weight of crystalline oxalic acid
The molecular weight can be calculated by summing the atomic weights of all the atoms in the formula:

- Carbon (C): 2 atoms × 12 g/mol = 24 g/mol
- Hydrogen (H): 2 atoms from oxalic acid + 4 atoms from 2 water molecules = 6 atoms × 1 g/mol = 6 g/mol
- Oxygen (O): 4 atoms from oxalic acid + 2 atoms from 2 water molecules = 6 atoms × 16 g/mol = 96 g/mol

Now, we can sum these values:
\[ \text{Molecular weight} = 24 + 6 + 96 = 126 \text{ g/mol} \]

### Step 3: Determine the N factor (valence)
The N factor for oxalic acid is 2 because it can donate two protons (H⁺ ions) in a reaction. This is important for calculating the equivalent weight.

### Step 4: Calculate the equivalent weight
The equivalent weight is calculated using the formula:
\[ \text{Equivalent weight} = \frac{\text{Molecular weight}}{\text{N factor}} \]
Substituting the values we have:
\[ \text{Equivalent weight} = \frac{126 \text{ g/mol}}{2} = 63 \text{ g/equiv} \]

### Final Answer
The equivalent weight of crystalline oxalic acid is **63 g/equiv**.

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