Equivalent weight of oxalic acid salt in following reaction is :( Atomic masses:O=16,C=12,K=39) `H_(2)C_(2)O_(4)+Ca(OH)_(2) toCaC_(2)O_(4)+H_(2)O`

Options

A. 90
B. 45
C. 64
D. 128

Answer

To find the equivalent weight of oxalic acid (H₂C₂O₄) in the given reaction, we can follow these steps:

### Step 1: Determine the Molecular Weight of Oxalic Acid
The molecular weight of a compound is calculated by summing the atomic masses of all the atoms in the molecule.

- For H₂C₂O₄:
- Hydrogen (H): 2 atoms × 1 g/mol = 2 g/mol
- Carbon (C): 2 atoms × 12 g/mol = 24 g/mol
- Oxygen (O): 4 atoms × 16 g/mol = 64 g/mol

Now, add these values together:
\[ \text{Molecular weight of H}_2\text{C}_2\text{O}_4 = 2 + 24 + 64 = 90 \text{ g/mol} \]

### Step 2: Determine the Basicity of Oxalic Acid
Basicity refers to the number of replaceable hydrogen ions (H⁺) in an acid.

- Oxalic acid (H₂C₂O₄) can donate 2 protons (H⁺) when it reacts with a base, which means it is a dibasic acid. Therefore, the basicity is 2.

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

Substituting the values we have:
\[ \text{Equivalent Weight} = \frac{90 \text{ g/mol}}{2} = 45 \text{ g/equiv} \]

### Conclusion
The equivalent weight of oxalic acid in the given reaction is **45 g/equiv**.

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