Question

The constant pressure molar heat capacity, Cp,m of nitrogen is 29.125 J K-1 m-1 at ~298 K. Calculate the change in internal energy ΔU when 1.4 kg of nitrogen gas is heated from 250 K to 320 K.

Answer 1

For an ideal gas at constant pressure, it takes more heat to achieve the same temperature change than it does at constant volume. At constant volume all the heat added goes into raising the temperature. At constant pressure some of the heat goes to doing work