Question

An aqueous solution of 6.3 g of oxalic acid dihydrate $\left(C_2{H}_2{O}_4.2H_{2}O\right)$ has a volume equal to 250 mL. The volume of 0.1 M $NaOH$ required to completely neutralize 10 mL of this solution is:

• A. 60 mL
• B. 10 mL
• C. 40 mL
• D. 80 mL

Answer 1

The correct option is C 40 mL

Number of moles of oxalic dihydrate, $C_2{H}_2{O}_4.2H_{2}O=\frac{6.3}{126}=0.05$

Molarity of oxalic acid solution
$=\frac{0.05}{250}\times 1000=0.2M$

Since, the resultant solution will be neutral, and 1 mol of oxalic acid gives 2 mol of $H^{+}$ ion.
So, $M_1{V}_1=M_2{V}_2$
Where $M_1$ and $V_1$ are the molarity of $H^{+}$ ion and the volume of the acid solution.
$M_2$ and $V_2$ are the molarity of $O{H}^{-}$ ion and the volume of the basic solution.
$(2\times 0.2\times 10)=(0.1\times V_2)$
On solving, volume = 40 mL
Therefore, 40 mL of 0.1 M $NaOH$ is required to neutralize the oxalic acid solution.