1. The problem statement, all variables and given/known data 4.48 L of an ideal gas at STP requires 12 cal to raise the temperature by 15°C at constant volume. The Cp of the gas is (in cal)? 3. The attempt at a solution ΔU = nCvΔT I can find out C_v from above equation but how to get C_p? I assume it would be wrong to use this equation ΔQ=nCpΔT as the process is carried out at constant volume and not pressure.