Question

Which of the following does not show a positive deviation from Raoult's Law?

• A. Benzene-chloroform
• B. Benzene-acetone
• C. Benzene-ethanol
• D. Benzene-carbon tetrachloride

Answer 1

The correct option is A

Benzene-chloroform

Explanation for the correct options:

Option A is the correct answer.

• Raoult's law: For a solution of volatile liquids, the partial vapor pressure of each component of the solution is directly proportional to its mole fraction present in the solution.
• When there is a deviation in the concentration range of Raoult's law, it is a non-ideal solution.
• It helps us to speculate that the vapor pressure is more or less than the projected vapor pressure for a particular solution
• Greater means positive deviation and lesser means a negative deviation.
• Between the chloroform and benzene molecules, a connection could be developed through hydrogen bonding, which results in a decrease in vapor pressure for each component.

Explanation for the incorrect options:

when bonds of any compound gets weaker, a positive deviation is generally experienced, and hence.

• Option (B) ,positive (+ve) deviation is shown.
• Option (C), positive (+ve) deviation is shown.
• Option (D), positive (+ve) deviation is shown.

Therefore, option (A) is the correct answer.