Resistance and conductivity of a cell containing 0.1 M KCl solution at 298 K are 115 ohm and $1.90 \times 10^{-6} \mathrm{~S} \mathrm{~cm}^{-1}$ respectively. What is the value of cell constant?

10 g each of $\mathrm{NH}_3, \mathrm{~N}_2, \mathrm{Cl}_2$ and $\mathrm{H}_2 \mathrm{~S}$ are expanded isothermally and reversibly at same temperature. Identify gas that performs maximum work.

A solution of non volatile solute has boiling point elevation 0.5 K . Calculate molality of solution $\left[\mathrm{K}_{\mathrm{b}}=2.40 \mathrm{~K} \mathrm{~kg} \mathrm{~mol}^{-1}\right]$.

Chlorine has two isotopes ${ }^{35} \mathrm{Cl}$ and ${ }^{37} \mathrm{Cl}$ with average atomic mass of 35.5 . What is the ratio of their relative abundance respectively?