Question

The freezing point depression constant (Kf) 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):​

Answer 1

Answer:

0.40k is the answer to the question

Answer 2

Given:

The freezing point depression constant (Kf) of benzene is 5.12 K kg mol-1. molality containing a non-electrolyte solute is 0.078 m.

To find:

Depression in freezing point.

Calculation:

General expression for depression in freezing point in solutions is :

$\boxed{ \rm{\Delta T = i \times K_{f} \times m}}$

For a non-electrolyte solute , the Van't Hoff Factor will be one (1).

Now , putting available values:

$= > \rm{\Delta T = 1 \times K_{f} \times m}$

$= > \rm{\Delta T = 1 \times 5.12 \times 0.078}$

$= > \rm{\Delta T = 0.399}$

$= > \rm{\Delta T \approx 0.4}$

So, the depression in freezing point will be :

$\boxed{\bf{\Delta T \approx 0.4 \: K }}$