Chemistry - Thermodynamics - I Question with Solution | TestHub
ChemistryThermodynamics - IWorkHard2 minQB
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Passage / Comprehension
An ideal gas (CP/Cv = γ) is expanded so that the amount of heat transferred to the gas is equal to one-third of the decrease in its internal energy.
What is the magnitude of work performed by one mole of the gas when its volume increases 16 times, if the initial temperature of the gas is 400 K? Cv,m for the gas is 1.5R. (R = 2 cal/mol K)
Options:
Answer:
B
Solution:
γ = 5/3, so 3(γ-1)/4 = 1/2. T2 = T1(V1/V2)1/2 = 400/√(16) = 100 K. Δ U = 1.5R(100-400) = -450R = -900 cal. Since q = -Δ U/3, w = q - Δ U = -4/3Δ U = 4/3× 900 = 1200 cal. (The value 900 cal is only |Δ U|.) Matches (b).
Stream:JEESubject:ChemistryTopic:Thermodynamics - ISubtopic:Work
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