NEETChemistrySolutions
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): A mixture of carbon disulfide and acetone shows positive deviation from Raoult's law. Reason (R): In this mixture, the solute-solvent (A-B) dipolar interactions are weaker than the solute-solute (A-A) and solvent-solvent (B-B) interactions. In the light of the above statements, choose the most appr
Options
- ABoth (A) and (R) are correct but (R) is not the correct explanation of (A)
- B(A) is correct but (R) is not correct
- C(A) is not correct but (R) is correct
- DBoth (A) and (R) are correct and (R) is the correct explanation of (A)
Correct answer
D. Both (A) and (R) are correct and (R) is the correct explanation of (A)
Step-by-step solution
Both Assertion (A) and Reason (R) are correct statements. In a mixture of carbon disulfide and acetone, the carbon disulfide molecules get between the acetone molecules and break the dipole-dipole interactions between them. As a result, the new solute-solvent (A-B) interactions are weaker than the original solute-solute (A-A) and solvent-solvent (B-B) interactions. Because the intermolecular forces are weakened, the molecules have a higher escaping tendency, which increases the vapour pressure of the solution above