0.45 g of an acid ( mol. Mass = 90 ) is neutralised by 20 mol of 0.5 N NaOH solution. The basicity of the acid is :

Options

A. 1
B. 2
C. 3
D. 4

Answer

B

Explanation

20 ml of 0.5 N NaOH solution neutralise acid = 0.45 g
1000 ml of 1 N NaOH solution neutralise acid
`=(0.45 xx 1000 xx 1)/(20 xx 0.5)`
= 45 g
Eq. wt of acid = 45 g
Basicity `=("Mol. wt")/("Eq. wt ")=(90)/(45)=2`