Practice question · Multiple choice
Why is always larger than for a gas?
Hints
- Ask where the heat goes in each case.
- At constant volume all of it raises the internal energy; at constant pressure some is spent pushing the surroundings back.
Show the answer
D. At constant pressure the gas also does expansion work, so more heat is needed
Why
At constant volume every joule raises . At constant pressure the gas also expands and does work on its surroundings, so it needs extra heat for the same temperature rise, precisely per degree for an ideal gas.
Practise The First Law and Heat Capacities
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