An ideal gas has molar specific heat Cp at constant pressure. When the temperature of n moles is increased by AT the increase in the internal energy is:
Correct answer: C. n(Cp - R) △T
- A. nCp △T
- B. n(Cp + R) △T
- C. n(Cp - R) △T
- D. n(2Cp + R) △T
Explanation
This is the correct option. It represents the increase in internal energy of an ideal gas when the temperature is increased by ΔT\Delta TΔT. In this equation, nnn is the number of moles, CpC_pCp is the molar specific heat at constant pressure, and RRR is the ideal gas constant. The term (Cp−R)(C_p - R)(Cp −R) reflects the relationship between the specific heats at constant pressure and constant volume. This option shows how internal energy is dependent on the change in temperature and the difference between the specific heats.
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About Molar Specific Heat of a Gas
Molar specific heat is the heat required to raise the temperature of one mole of a gas by one kelvin, expressed through Q = nCΔT. Questions compare the constant volume value Cv with the constant pressure value Cp, apply the ideal gas relation Cp − Cv = R, and identify how the thermodynamic process affects heat capacity.
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