Q. An aqueous solution is 1.00 molal in KI. Which change will cause the vapour pressure of the solution to increase?
A) Addition of water
B) Addition of NaCl
C) Addition of Na₂SO₄
D) Addition of 1.00 molal KI
Explanation
[Solution from source] Vapour pressure lowering depends on solute concentration. Adding water dilutes the solution, so its vapour pressure rises. Adding NaCl or Na₂SO₄ adds solute and lowers it; adding more 1.00 molal KI leaves the concentration unchanged. Answer (1).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.