Two liquids X and Y boil at 110°C and 130°C respectively. Which of them has higher vapour pressure at 50°C?
Answer: X — the lower-boiling liquid is more volatile and has the higher vapour pressure at any given temperature.
Solution
A liquid with the lower boiling point is the more volatile one.
X boils at 110°C (< 130°C), so at 50°C liquid X has the higher vapour pressure.
X boils at 110°C (< 130°C), so at 50°C liquid X has the higher vapour pressure.
CBSE Class 12 Board · 2005 · Delhi Compartment; also All India 2004 Compartment · Subjective