Question

Camphor is used as solvent to determine molar mass of non-volatile solute by Rast method because for camphor :

• A. it is readily available
• B. it is volatile
• C. molal depression constant is high
• D. it is solvent for organic substances

Answer 1

The correct option is C molal depression constant is high

Camphor is used as solvent to determine molar mass of non-volatile solute by Rast method because for camphor its molal depression constant is high(cryoscopic constant value is high).Camphor also possess high melting point.
Due to higher $K_f$ of camphor $\left(40Kmolalit{y}^{-1}\right)$ about 20 times more than $K_f$ (1.86) of water, the depression is 20 times more in case of camphor used as solvent than water.