Question

What is the freezing point of a 1.85 m solution of a non-volatile nonelectrolyte solute in nitrobenzene?

Short answer

The boiling point of the given solutionis -9.3^oC.

Step-by-step solution

Freezing Point

At standard atmospheric pressure, the freezing point may be defined as the temperature at which the liquid is converted into solid.

\({\bf{\Delta }}{{\bf{T}}_{\bf{f}}}{\bf{ = }}{{\bf{K}}_{\bf{f}}}{\bf{m}}\)

where,

\({{\bf{K}}_{\bf{f}}}\)= Freezing point depression constant

m = Molality of the solute

Explanation

Molality of Nitrobenzene = 1.85m

\(\)

Change in freezing point:

\({\rm{\Delta }}{{\rm{T}}_{\rm{f}}}{\rm{ = }}{{\rm{K}}_{\rm{f}}}{\rm{m = 5}}{\rm{.12 ^\circ C}}{{\rm{m}}^{{\rm{ - 1}}}}{\rm{ \times 1}}{\rm{.85 m = 9}}{\rm{.3 ^\circ C}}\) \(\)

Freezing point of the solvent:

\({\rm{Freezing point Temperature = 0^\circ C -- 9}}{\rm{.3 ^\circ C = - 9}}{\rm{.3 ^\circ C}}\)