Question

If the observed and normal osmotic pressures of $1\%$ solution are $5.7$ and $3.0$ atm, the degree of dissociation of $NaCl$ is:

• A. $0.9$
• B. $1.0$
• C. $0.57$
• D. $0.3$

Answer 1

The correct option is A $0.9$

i $=\frac{obseerved}{normal}=\frac{5.7}{30}\Rightarrow 1.9$

$m\Rightarrow 2$ for NaCl

$\alpha =\frac{i-1}{m-1}\Rightarrow \frac{1.9-1}{2-1}\Rightarrow 0.9$