Question

$0.45g$ of acid (molecular weight $=90$) was exactly neutralized by $20mL$ of $0.5NNaOH$. Basicity of the acid is:

• A. $1$
• B. $2$
• C. $3$
• D. $4$

Answer 1

Answer: (B)

$2$

Let the $n_{factor}$ be $n$.

Moles of acid $=\frac{0.45}{90}=5milimoles$

Comparing equivalents of acid and $NaOH$

$5\times n=0.5\times 20$

$n=2$

For acid, $n_{factor}=basicity$

$\therefore$ Basicity is $2$