The molar heat capacity at constant volume of a gas is found to be 20.74 J/mol · K.What is the molar heat capacity at constant pressure of this gas? (The ideal-gas law constant is R = 8.31 J/mol · K)

Question

Quizplus · Accepted Answer

The relationship between molar heat capacity at constant pressure (Cp) and molar heat capacity at constant volume (Cv) for an ideal gas is:

Cp - Cv = R

where R is the ideal-gas law constant.

Rearranging this equation, we can solve for Cp:

Cp = Cv + R

Plugging in the given value of Cv (20.74 J/mol · K) and R (8.31 J/mol · K), we get:

Cp = 20.74 J/mol · K + 8.31 J/mol · K = 29.05 J/mol · K

Therefore, the molar heat capacity at constant pressure of this gas is approximately 29.0 J/mol · K, which is closest to choice B.

The Molar Heat Capacity at Constant Volume of a Gas