Answered

Compared to pure water, an aqueous solution of calcium chloride has a

(1) higher boiling point and higher freezing point

(2) higher boiling point and lower freezing point

(3) lower boiling point and higher freezing point

(4) lower boiling point and lower freezing point

Verified Answer :

Edufirst

Answer: option (2) higher boiling point and lower freezing point.


Explanation:


Colligative properties are those properties of solution that depend on the concentraion of the solute.


Increase of boling point and depression of freezing point are two of those colligative properties.


Regarding the boiling point, as some impurities (in this case the solute calcium chloride) are present in the solvent (water) ,at the same temperature, less molecules of water will reach the surface to escape, at a given temperature. Hence, you have to increase the temperature to manage that the number of molecules and their speed increase and so all the molecules can escape fro, the liquid phase to form the gas. So, the boiling point of the water with the salt in it will be higher than the boiling point of pure water.


As for the freezing point, in a solution the particles of solute interfere with the attractive forces between the molecules of water avoiding that the solvent passes to solid state at the normal freezing point. Hence, the temperature to freeze will be lower.

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