Question

The freezing point depression constant (K_f) of benzene is 5.12 K kg mol⁻¹. The freezing point depression for the solution of molality 0.078 m containing a non-electrolyte solute in benzene is ______. (rounded off upto two decimal places)

Options

• 0.20 K

• 0.80 K

• 0.40 K

• 0.60 K

Answer 1

The freezing point depression constant (K_f) of benzene is 5.12 K kg mol⁻¹. The freezing point depression for the solution of molality 0.078 m containing a non-electrolyte solute in benzene is 0.40 K.

Explanation:

Given: K_f = 5.12 K kg mol⁻¹

Molality (m) = 0.078 mol/kg

Solute is a non-electrolyte (i) = 1

ΔT_f = i K_f m

= 1 × 5.12 × 0.078

= 0.39936 K

= 0.40 K