Question

The silver salt of a monobasic acid on ignition gave $60\%$ of $Ag$.The molecular mass of the acid is:

• A. 37
• B. 33
• C. 73
• D. 77

Answer 1

The correct option is C 73

Let '$E$' be the equivalent mass of silver salt $\left(Ag\right)$.

Therefore,

$\frac{\text{Eq. mass of silver salt}}{\text{Eq. mass of silver}}=\frac{\text{Mass of acid taken}}{\text{Mass of asilver left}}$

$\frac{E}{108}=\frac{100}{60}$

$\Rightarrow E=180g$

$\therefore$ Eq. mass of acid $=E_{salt}-E_{Ag}+\text{basicity}$

$\Rightarrow$ Eq. mass of acid $=180-108+1=73g$

Now,

molecular mass of acid $=$ basiciy $\times$ Eq. mass

$\therefore$ Molecular mass of acid $=1\times 73=73g$