Reversible Non-Flow Processes – Which Types Can Be Reversible? Identify which of the listed non-flow processes can, in principle, be carried out reversibly for a closed system if executed quasi-statically with no friction, finite temperature differences, or other irreversibilities.

Introduction / Context:Reversibility is an idealization used to define limits and to derive reference formulas. Many named processes (constant volume, constant pressure, or pv = constant) can be reversible if executed infinitely slowly with perfect insulation or heat transfer at infinitesimal temperature differences and without friction.

Given Data / Assumptions:

• Closed system undergoing a path in p–v–T space.
• Quasi-static evolution with no dissipative effects (no friction, turbulence, electrical resistance, or mixing).
• Heat transfer, if present, occurs with negligible temperature difference.

Concept / Approach:

Reversibility depends on how a process is executed, not on its label. Isochoric (v = constant), isobaric (p = constant), and hyperbolic (pv = constant) paths can all be traced reversibly if constraints remove sources of entropy generation. Any of these processes may also be irreversible if conducted rapidly or with finite gradients.

Step-by-Step Solution:

Verification / Alternative check:

T–s diagrams for reversible paths show ds integrals that match q_rev/T with no excess entropy generation. Any deviation producing positive S_gen marks irreversibility.

Why Other Options Are Wrong:

“None of these” ignores the central idea that reversibility is about execution conditions, not process names. Picking only one would be arbitrarily restrictive.

Common Pitfalls:

Equating “adiabatic” with “reversible” automatically; running processes quickly and still labeling them reversible; forgetting surface friction at pistons causes S_gen.

Final Answer:

all of these