If a gas expands against a constant external pressure, the work done by the gas

If a gas expands against a constant external pressure, the work done by the gas is given by:

If a gas expands against a constant external pressure, the work done by the gas is given by:

Correct Answer: W = P_ext * ΔV

Step 1: Understand that when a gas expands, it pushes against something (the external pressure).
Step 2: Recognize that the work done by the gas is related to how much it expands (this is called ΔV, or change in volume).
Step 3: Know that the external pressure (P_ext) is the constant pressure the gas is pushing against during its expansion.
Step 4: Combine these ideas into the formula: Work (W) is equal to the external pressure (P_ext) multiplied by the change in volume (ΔV).
Step 5: Write the formula as W = P_ext * ΔV to express the work done by the gas.

Work Done by Gas – The work done by a gas during expansion is calculated using the formula W = P_ext * ΔV, where P_ext is the external pressure and ΔV is the change in volume.
Constant External Pressure – The scenario assumes that the external pressure remains constant throughout the expansion process, which simplifies the calculation of work.
Sign Convention – Understanding the sign convention for work is crucial; work done by the system (gas) is typically considered negative in thermodynamics.