Physics · University
Reversible isothermal ideal-gas work · formula reference
Work is positive for expansion; the process is reversible and isothermal for an ideal gas.
Formula
Work is positive for expansion; the process is reversible and isothermal for an ideal gas.
Wby = nRT ln(Vf/Vi)
Worked example
An ideal gas of 9 mol expands reversibly and isothermally at 520 K until Vf/Vi=7. Using R=8.314 J/(mol·K), find work done by the gas. Round the final result to 4 decimal places if needed. Answer in J.
Wby = (9)(8.314)(520) ln(7).
75714.4299 J
Prerequisites and checking
Algebra, calculus and the stated physical model. Keep units and rounding consistent. State the model conditions before applying the formula.
Further reading and review references
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