Question

The molecular weight of an acid is 90 gm. If 0.9 gm of acid is completely neutralised by 20c.c. of 1N base, basicity of the acid is:

• A. $1$
• B. $2$
• C. $3$
• D. $4$

Answer 1

The correct option is B $2$

$M=\frac{N}{\eta }$ where $\eta$ is the basicity of the acid.

Equivalence of acid $=$ Equivalence of base

$\frac{0.9}{90}\times \eta =1\times \frac{20}{1000}$

$\eta =\frac{.02}{0.01}$

$\eta =2$