Key Idea Vapour pressure depends upon the surface area of the solution. Larger the surface area, higher is the vapour pressure. Addition of solute decreases the vapour pressure as some sites of the surface are occupied by solute particles, resulting in decreased surface area. However, addition of solvent, ie, dilution, increases the surface area of the liquid surface, thus results in increased vapour pressure. Hence, addition of water to the aqueous solution of (1 molal) KI, results in increased vapour pressure.
An aqueous solution is 1.00 molal in KI. Which change will cause the vapour pressure of the solution to increase ?
NEET UG 2010 — Chemistry Physical Chemistry
An aqueous solution is 1.00 molal in KI. Which change will cause the vapour pressure of the solution to increase ?
Held on 30 Apr 2010 · Verified 9 Jul 2026.
Options
- A
Addition of NaCl
- B
Addition of Na2SO4
- C
Addition of 1.00 molal KI
- D
Addition of water
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