2020 ThermodynamicsThermodynamic Processes – Free Expansion Medium Question 12 of 54 in Thermodynamics

Two cylinders A and B of equal capacity are connected to each other via a stop cock. A contains an ideal gas at standard temperature and pressure. B is completely evacuated. The entire system is thermally insulated. The stop cock is suddenly opened. The process is:

A adiabatic
B isochoric
C isobaric
D isothermal

The answer is A.

Solution

The entire system is thermally insulated, so no heat exchange takes place with the surroundings (Q = 0). Hence the process is adiabatic (it is a free expansion into vacuum).

Concept free expansion of a gas

Thermodynamics in past papers

54 questions from this chapter have appeared across 26 exam years.