A gas expands isothermally and irreversibly. -ΔS_surr is

Question

Quizplus · Accepted Answer

Since the process is irreversible, ΔS is always greater than or equal to zero. In an isothermal process, ΔU is equal to zero. Therefore, ΔS_surr is equal to -Q/T, where Q is the heat absorbed by the surroundings and T is the temperature of the system. As the gas expands, work is done by the gas, so Q is negative. Therefore, -Q/T is a positive value, meaning ΔS_surr is less than zero.

A Gas Expands Isothermally and Irreversibly