Solutions Question 75
Question: 1.00 gm of a non-electrolyte solute dissolved in 50 gm of benzene lowered the freezing point of benzene by 0.40 K. $ K_{f} $ for benzene is 5.12 kg mol-1. Molecular mass of the solute will be [DPMT 2004]
Options:
A) $ 256,g,mo{l^{-1}} $
B) $ 2.56,g,mo{l^{-1}} $
C) $ 512\times 10^{3},g,mo{l^{-1}} $
D) $ 2.56\times 10^{4},g,mo{l^{-1}} $
Show Answer
Answer:
Correct Answer: A
Solution:
By using, $ m=\frac{K_{f}\times 1000\times w}{\Delta T_{f}\times {W_{Solvent,}}(gm)} $
$ =\frac{5.12,\times 1000\times 1}{0.40\times 50} $
$ =256,gm/mol $ Hence, molecular mass of the solute $ =256,gm,mo{l^{-1}} $
