Question

Camhor is used as solved to determine the molecule weight of non-volatile solute by Rast method because for camphor:-

• A. Molal depression constant is high
• B. Melting point in high
• C. Being cheap
• D. All of these

Answer 1

The correct option is A Molal depression constant is high

Camphor is used for the determination of molecular masses of solute because its molal depression constant is very high. Its value is about $40K{m}^{-1}$. Molal depression constant is defined as the depression in freezing point produced when 1 mole of solute is dissolved in 1Kg of solvent.

Since, $\Delta T_f=K_{f}m$

Where, $\Delta T$ is the freezing point of pure solvent.

$m$ is the molality of the solution.

$K_f$is the molal freezing point depression constant