Chemistry - Thermodynamics - I Question with Solution | TestHub
ChemistryThermodynamics - IHeat & Heat CapacityHard2 minQB
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A person of mass 60 kg produces 10.08 MJ of energy per day through metabolism, of which 25% leaves as mechanical work done on the surroundings and the rest appears as heat. Treat the body as an isolated system for the heat part: 70% of its mass is water (4.2 J/K-g) and the remaining 30% has a specific heat of 1.4 J/K-g. What temperature rise would the body experience in one day?
Options:
Answer:
D
Solution:
Heat retained = 0.75 × 10.08 = 7.56 MJ. Heat capacity = 42000 × 4.2 + 18000 × 1.4 = 1.764×105 + 0.252×105 = 2.016×105 J/K. Δ T = 7.56×106 / 2.016×105 = 37.5 K. (Ignoring the work loss gives 50 K; treating the whole body as water gives 30 K with work loss, 40 K without.) Matches (d).
Stream:JEESubject:ChemistryTopic:Thermodynamics - ISubtopic:Heat & Heat Capacity
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