Question

$0.45 \,g$ of acid molecular weight $90$ is neutralised by $20\, ml$ of $0.5\,N$ caustic potash. The basicity of acid is

• A. 1
• B. 2
• C. 3
• D. 4

Answer 1

Answer: (B)

Let the $n _{\text {factor }}$ be $n$.
Moles of acid $=\frac{0.45}{90}=5$ milimoles
Comparing equivalents of acid and $NaOH$
$5 \times n=0.5 \times 20$
$n =2$
For acid, $n _{\text {factor }}=$ basicity
$\therefore $ Basicity is $2$