Consider the quasi-static adiabatic expansion of an ideal gas from an initial state i to a final state f. Which is the following statements is NOT true?
A. No heat flows into or out of the gas.
B. The entropy of state i equals the entropy of state f.
C. The change of internal energy of the gas is −∫ PdV.
D. The mechanical work done by the gas is ∫ PdV.
E. The temperature of the gas remains constant.
(GR0177 #36)
Solution:
A (not) dia (through) batic (passable) = no heat flow, container is well insulated
(A) and (B) are TRUE.
Q = 0
∆U = −W = −∫ PdV
(C) TRUE.
Definition of mechanical work: W = ∫ PdV
(D) TRUE.
T constant is Isothermal not adiabatic
(E) FALSE
Answer: E
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