Question

The vapour density of completely dissociated $NH_{4}Cl$ would be

• A. Slight less than half that of $NH_{4}Cl$
• B. Half that of $NH_{4}Cl$
• C. Double that of $NH_{4}Cl$
• D. Determined by the amount of solid $NH_{4}Cl$ in the experiment

Answer 1

Answer: (B)

$\frac{\text{Normal molecular weight}}{\text{experimental molecular wt.}} =1+\alpha$
$NH_{4}Cl \rightleftharpoons NH_{3} +HCl$
$\because \alpha=1$
$\therefore $ Experimental Molecular wt. $=\frac{nor.mol.wt.}{2}$