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Specific heats for an ideal gas: compare cp and cv State how the specific heat at constant pressure (cp) compares to the specific heat at constant volume (cv). Choose the correct comparison.

Q: Specific heats for an ideal gas: compare cp and cv State how the specific heat at constant pressure (cp) compares to the specific heat at constant volume (cv). Choose the correct comparison.

Concept/Approach At constant pressure, part of the heat goes into doing boundary work during expansion; hence more heat per kelvin is required. For an ideal gas: cp − cv = R and the ratio γ = cp/cv > 1. Final Answer cp is greater than cv.

Difficulty: Easy

cp is greater than cv
cp equals cv
cp is less than cv
No definite relation

Correct Answer: cp is greater than cv

Explanation:

Concept/Approach

At constant pressure, part of the heat goes into doing boundary work during expansion; hence more heat per kelvin is required.
For an ideal gas: c_p − c_v = R and the ratio γ = c_p/c_v > 1.

Final Answer
c_p is greater than c_v.

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