JEE Main · 2023 · 13 Apr 2023 · Shift 2 · Chemical Thermodynamics

What happens when methane undergoes combustion in systems A and B respectively?

(A)System A: Temperature rises; System B: Temperature remains same✓ Correct
(B)System A: Temperature falls; System B: Temperature rises
(C)System A: Temperature falls; System B: Temperature remains same
(D)System A: Temperature remains same; System B: Temperature rises

Answer: (A)

Solution

In System A (adiabatic boundary), no heat exchange with surroundings is allowed. The heat generated from methane combustion cannot escape, causing the temperature to rise. In System B (diathermic boundary), heat can flow freely to the surroundings, maintaining constant temperature. Therefore, temperature rises in A and remains constant in B.

JEE Main · 2023 · 13 Apr 2023 · Shift 2 · Single correct option

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