Question

A vessel contains equal number of
molecules of hydrogen and helium
under a pressure of 800 mm at0°C. If all
the helium molecules are
removed from the vessel, the pressure in
the vessel becomes
(A) 600 m.m
S @
(B) 200 m.m
(C)
400 m.m
(D)
500 m.m​

Answer 1

Since pressure at constant temperature and volume is directly proportional to the no. of gas molecules,

The pressure becomes exactly half of the initial pressure as the no. of molecules are halved.

Apply Avagadro's law.

H2 and He gas molecules are extremely smaller in size posses no attraction and only undergo positive deviation from Z=1, even under the application of little force.

Answer 2

Answer: 400 mm

Since the pressure at constant temperature and volume is directly proportional to the no. of gas molecules,

The pressure becomes exactly half of the initial pressure as the no. of molecules is halved.

Apply Avagadro's law.

Hope it helps