Question

Identify the correct statement from the following.

• A. The vapor pressure of solution containing chloroform and acetone is lower than vapor pressure of pure chloroform and acetone at same temperature.
• B. The vapor pressure of aqueous solution containing nonvolatile solute increases with increasing solute concentration.
• C. The vapor pressure of liquid decreases with increase in temperature.
• D. The lowering in vapor pressure in dilute solutions is greater than concentrated solutions at the same temperature.

Hint:

Chloroform and acetone show negative deviation from Raoult's law, so their solution has a lower vapour pressure than the ideal case.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept
Chloroform and acetone form hydrogen bonds with each other, giving a negative deviation from Raoult's law.

Step 2: Check each statement
(A) Because of the negative deviation, the mixture has a lower vapour pressure than expected, so it is correct for the chloroform-acetone solution.
(B) A non-volatile solute lowers the vapour pressure, so the statement is false.
(C) The vapour pressure of a liquid increases with temperature, so this is false.
(D) The lowering is greater in concentrated solutions, so this is false.

Step 3: Compare the options
The first statement is the correct one, which is option (A).

Final Answer:
The chloroform-acetone solution has a lower vapour pressure than the pure liquids. \[ \boxed{\text{(A) }\text{The vapor pressure of solution containing chloroform and acetone is lower than vapor pressure of pure chloroform and acetone at same temperature.}} \]