Here we extend a set of earlier articles that dealt with time-dependent irreversible processes across a thin boundary separating a system from its surroundings. The entropy change for irreversible transfers of heat, work, and matter in this compound system is examined for a one component condensed phase for which temperature, pressure, and mole numbers are the control variables. The required fundamental relations are collected and evaluated to generate an expression for the entropy change in terms of experimentally determinable variables. Contributions to the entropy change from heat exchange, work performance, and material transfer are evaluated for two distinct time-dependent paths. While contributions from each element differ for the two cases, the sum of all three elements remains identical for both time variations, as is consistent with entropy being a function of state. The net entropy change upon irreversibly cycling is also assessed.
Key words: Irreversible Processes, Transfer Across Boundaries, Entropy of Irreversible Transfers,
Quasistatic Irreversible Processes
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