Question

What is equivalent weight of crystalline oxalic acid?

Answer 1

Equivalent weight:

• It is expressed as the ratio of atomic weight or molecular weight of a given species to its n-factor.
• It depends on the type of substance if it is an acid, molecule, ion or a base.

Formula used:

• $\text{Equivalent weight of acid}=\frac{\text{Molecular weight of acid}}{\text{Basicity of acid}}$

Or,

• $\text{Equivalent weight of base}=\frac{\text{Molecular weight of base}}{\text{Acidity of base}}$

Step 1: Given,

• Chemical formula of crystalline oxalic acid is $\mathrm{HOOC}-\mathrm{COOH}.2{\mathrm{H}}_2\mathrm{O}$.
• Molecular weight of crystalline oxalic acid $=126\mathrm{g}{\mathrm{mol}}^{-1}$

Step 2: Determine the equivalent weight of crystalline oxalic acid.

• The oxalic acid can donate two hydrogens. So, the basicity of acid is $2$.
• $\text{Equivalent weight of acid}=\frac{\text{Molecular weight of acid}}{\text{Basicity of acid}}$
• $\text{Equivalent weight of oxalic acid}=\frac{126\mathrm{g}{\mathrm{mol}}^{-1}}{2}$
• $\text{Equivalent weight of oxalic acid}=63\mathrm{g}{\mathrm{eq}}^{-1}{\mathrm{mol}}^{-1}$

Therefore, the equivalent weight of crystalline oxalic acid is $63\mathrm{g}{\mathrm{eq}}^{-1}{\mathrm{mol}}^{-1}$.