Question

In a vessel, the gas at a pressure P. If the mass of all molecules is halved and their speed is doubled, then the resultant pressure will be ___________

(a) 4P

(b) 2P

(c) P

(d) P/2

The question was asked in an interview for job.

My question is based upon Gases and Reactions topic in portion Kinetic Theory of Gases of Engineering Physics I

Answer 1

Right choice is (c) P

To explain: According to the kinetic theory of gases, the pressure exerted by a gas,

P=1/3×mn/V v^2

P^‘/P=2

P^‘=2P.