The weight of oxalic acid dihydrate is 126. Its equivalent weight is

Options

A. 36
B. 63
C. 126
D. 252

Explanation

To find the equivalent weight of oxalic acid dihydrate, we can follow these steps:

### Step 1: Identify the Molecular Weight
The molecular weight of oxalic acid dihydrate (C2H2O4·2H2O) is given as 126 g/mol.

### Step 2: Determine the Basicity
Oxalic acid (C2H2O4) has two carboxylic acid groups (COOH), which means it can donate two protons (H+ ions). Therefore, the basicity (n) of oxalic acid is 2.

### Step 3: Calculate the Equivalent Weight
The formula for calculating equivalent weight (EW) is:
\[ \text{Equivalent Weight} = \frac{\text{Molecular Weight}}{\text{Basicity}} \]

Substituting the values we have:
\[ \text{Equivalent Weight} = \frac{126 \, \text{g/mol}}{2} \]

### Step 4: Perform the Calculation
Now, we perform the division:
\[ \text{Equivalent Weight} = 63 \, \text{g/equiv} \]

### Conclusion
The equivalent weight of oxalic acid dihydrate is 63 g/equiv.

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