Q. A gas is collected over the water at $25℃.$ The total pressure of moist gas was $735\ mm$ of mercury. If the aqueous vapour pressure at $25℃$ is $23.8\ mm.$ Then the pressure of dry gas is
A) $760\ mm$
B) $758.8\ mm$
C) $710.8\ mm$
D) $711.2\ mm$
Explanation
(d) Total pressure $(P)$ of gas = Actual pressure of gas
$P_{a} +$ aqueous vapour pressure $(P_{V})$
$\Rightarrow P_{a} = P - P_{V} = 735 - 23.8 = 711.2mm$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.