[આપેલ :દ્રાવ્ય $A$નું મોલર દળ $93\, g\, mol ^{-1}$. પાણીનો મોલલ અવનયન અચળાક $1.86\, K \,kg\, mol ^{-1}$ ]
$0.2= i \times 1.86 \times \frac{0.7}{93} \times \frac{1000}{42}$
$i =\frac{0.2 \times 93 \times 6}{1.86 \times 100}$
$i =0.60$
$2 A \quad \rightleftharpoons A _{2}$
$1-\alpha$
$i =1-\alpha+\frac{\alpha}{2}$
$i =1-\frac{\alpha}{2}$
$1-\frac{\alpha}{2}=0.60$
$1-0.60=\frac{\alpha}{2}$
$\alpha=0.80$