Question

0.16 g of dibasic acid required 25 ml of decinormal NaOH solution for complete neutralisation. The molecular weight of the acid will be.

• A. 32
• B. 64
• C. 128
• D. 256

Answer 1

The correct option is C

128

Dibasic acids relate to an acid that contains two hydrogen atoms that can be replaced by metal ion

Given:

$25\mathrm{ml}$ of decinormal $\mathrm{NaOH}$ solution corresponds to

$25\times \frac{0.1}{1000}=0.0025\mathrm{gram}$

Therefore the molecular weight of the dibasic acid will be

$2\times \frac{0.16}{0.0025}=128\mathrm{g}/\mathrm{mol}$

Hence, Option(C) is correct.