Question

0.1 normal solution of $NaCl$ is found to be isotonic with 1.1 % solution of Urea. Calculate the apparent degree of ionisation of $NaCl$.

• A. $0.083$
• B. $8.3$
• C. $0.83$
• D. $0.42$

Answer 1

Answer: (C)

$0.83$

${\pi }_1={\pi }_2$
$i_1{M}_{1}RT=i_2{M}_{2}RT$
$i\times 0\cdot 1=\frac{1\cdot 1}{60}\times \frac{1000}{100}$
$i=\frac{11}{6}$
$i=1\cdot 83$
$1+\alpha (n-1)=1\cdot 83$
$\alpha =1\cdot {83}^{-1}$
$\alpha =\cdot 83$