Question

Explain how can a gas be expanded at constant temperature.

Answer 1

1. Consider a thermodynamic system consisting of an ideal gas confined to a cylinder with a movable, frictionless, and massless piston.
   
2. When the gas is heated slowly, in a controlled manner so that it expands at a constant temperature. It reaches the final volume V_f isothermally.
3. The system absorbs a finite amount of heat during this process.
4. But as the process is very slow, the temperature remains constant.
5. In this way, the gas expands and reaches final volume V_f at constant temperature.