229. Why is freezing point depression of 0.1 M sodium chloride solution nearly twice that of 0.1 M glucose solution?

Answer:

0.1M NaCl and0.1M glucose solution means that 0.1 moles of solute dissolve in 1L of solvent.

weight of solvent in both solution is same .
Dpression in freezing point can br calculated as :

$∆{\mathrm{T}}_{\mathrm{f}} = \frac{{\mathrm{K}}_{\mathrm{f}}\times {\mathrm{w}}_{\mathrm{B}}\times 1000}{{\mathrm{w}}_{\mathrm{A}} \times {\mathrm{M}}_{\mathrm{B}}}$

Where 
K_f = molal depression constant
w_B = weight of solute
w_A= weight of solvent
MB = molar mass of the solute

mass of NaCl = 58.69g/mol
mass of glucose = 180g/mol

The depression in freezingpoint is inversly proprotional to molar mass of solute thus more is molar mass of solute lesser is the depression in freezing point .
Thus it can explain that the NaCl wil be more than the glucose.