Concepts Of Physics MCQ Edition [Volume 2]PhysicsSpecific Heat Capacities of Gases
Suppose C_V and C_p denote the molar heat capacities of an ideal gas at constant volume and constant pressure, respectively. Which of the following expressions is a universal constant?
Options
- AC_p + C_V
- BC_p - C_V
- CC_p C_V
- DC_p C_V
Correct answer
B. C_p - C_V
Step-by-step solution
According to Mayer's relation for an ideal gas, the difference between the molar heat capacity at constant pressure ( C_p ) and the molar heat capacity at constant volume ( C_V ) is equal to the universal gas constant ( R ). C_p - C_V = R Since R is a universal constant, the expression C_p - C_V is a universal constant. The other expressions depend on the atomicity (degrees of freedom) of the gas and are not universal constants.