For a gas having molar mass M, specific heat at constant pressure per gm of gas is given by:
Correct answer: A. Cp = Cv + R/M
- A. Cp = Cv + R/M
- B. Cp = R/Cv
- C. Cp = γ * R
- D. Cp = Cv * M
Explanation
To find the specific heat at constant pressure per gram of a gas with molar mass M, we start with the fundamental thermodynamic relations: Cp - Cv = R and γ = Cp/Cv. Solving these equations for Cp, we derive the formula Cp = Cv + R/M. Here, R is the universal gas constant, and the division by M accounts for the conversion to specific heat per gram. The incorrect options misapply these relationships or omit necessary components like the molar mass M or the difference between Cp and Cv.
Last updated
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.
Practise Thermodynamics
714 free Thermodynamics MCQs from Physics, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Exams that ask Physics questions like this
Physics is on 13 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
Related questions
2 mole of an ideal monoatomic gas mix with 1 mole of a ideal diatomic gas. The Cp/Cv for the mixture is:
A fraction of internal energy is due to molecular vibration, which is different in different states of matter. Which of the following gives the correct order of fraction of internal energy due to molecular vibration?
A gas mixture consists of 2 moles of oxygen and 4 moles of a argon at temperature T. Neglecting all vibrational modes, the total internal energy of the system is:
A mixture of ideal gases N2 and He are taken in the mass ratio of 14 : 1 respectively. Molar heat capacity of the mixture at constant pressure is:
A monatomic gas is heated from temperature T1 and T2 under two different conditions at (i) constant volume and (ii) constant pressure. The change in U is: