Identify which liquid will have a higher vapour pressure at 90°C if the boiling points of two liquids A and B are 140°C and 180°C respectively.
Answer: Liquid A — its lower boiling point means it is more volatile.
Solution
The lower the boiling point, the more volatile the liquid and the higher its vapour pressure at any temperature below boiling.
A (b.p. 140°C) therefore has the higher vapour pressure at 90°C.
A (b.p. 140°C) therefore has the higher vapour pressure at 90°C.
CBSE Class 12 Board · 2020 · Subjective