The Molar Heat Capacity at Constant Volume of a Gas

Multiple Choice

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)

A) 12.4 J/mol · K
B) 29.0 J/mol · K
C) 33.2 J/mol · K
D) 41.5 J/mol · K
E) 8.28 J/mol · K