Question

An aqueous solution of $6.3$ g oxalic acid dihydrate is made up to $250$ mL. The volume of $0.1N$ NaOH required to completely neutralise $10$ mL of this solution is:

• A. $40$ mL
• B. $20$ mL
• C. $10$ mL
• D. $4$ mL

Answer 1

The correct option is A $40$ mL

The molecular weight of oxalic acid dihydrate $\left(C_2{H}_2{O}_4.2H_{2}O\right)$ is $126$ g/mol. It is a dibasic acid.

Its equivalent weight is $\frac{126}{2}=63$.

Its normality is $\frac{weight}{equivalentweight}\times \frac{1000}{VolumeinmL}=$. $\frac{6.3\times 1000}{63\times 250}=0.4N$.

But $N_1{V}_1=N_2{V}_2$,

Hence, $0.1V_1=0.4\times 10$

Thus, the volume of $0.1NNaOH$ required to completely neutralize $10$ mL of this solution is $40$ mL.

Hence, the correct option is $A$