Question

The osmotic pressure of a $0.1\text{M}$ aqueous solution of $MgC{l}_2$ at $300\text{K}$ is $4.92\text{atm}$. What will be the percentage ionisation of the salt?

• A. $49\%$
• B. $59\%$
• C. $79\%$
• D. $69\%$

Answer 1

The correct option is A $49\%$

$\pi =iCRT$
$4.92=i\times 0.1\times 0.0821\times 300$
$i=1.99$
$\alpha =\frac{i-1}{n-1}$
$=\frac{1.99-1}{3-1}=\frac{0.99}{2}=0.49$
$\alpha =49\%$