Question

A $1.17\%$ solution of $NaCl$ is isotonic with $7.2\%$ solution of glucose. Calculate the van’t Hoff factor of $NaCl$

Answer 1

For isotonic solution osmotic pressure should be the same
$\therefore \pi_{\left(NaCl\right)} =\pi_{\text{(glucose)}}$
$iC_{1}RT=C_{2} RT$
$iC_{1}=C_{2}$
$i \frac{\left(1.17/ 58.5\right)}{V}=\frac{7.2 /180}{V}$
$\Rightarrow i=\frac{7.2\times58.5}{1.17\times180}=2$