Question

what is the effect of impurities on freezeeing point of a solvent
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Answer 1

Explanation:

When an impurity is added its freezing point is lowered i.e. its freezing point decreases. The depression in freezing point increases with the increase in concentration of the solute because on adding the solute the vapour pressure of solution becomes lower than that of pure solvent.

Answer 2

Explanation:

When an impurity is added its freezing point is lowered i.e. its freezing point decreases.

The depression in freezing point increases with the increase in concentration of the solute because on adding the solute the vapour pressure of solution becomes lower than that of pure solvent. Since freezing point is the temperature at which vapour pressure of liquid and solid phase are equal, therefore, for the solution, this will occur at a lower-temperature.

For example freezing point of water is OoC under normal atmospheric pressure. If we add sugar or salt to this water its vapour pressure lowers and freezing point decreases.

Generally, when 1 mole of any non-electrolyte is dissolved in 1 litre of water the depression in freezing point of water is 1.860C.