One mole of an ideal monoatomic gas requires 210 J heat to raise the temperature by 10K, when heated at constant pressure. If the same gas is heated at constant volume to raise the temperature by 10K then heat required is

amount of heat required to raise the temperature of n mole of gas through dT is at constant volume is QV=nCVdT at constant pressure is QP=nCPdT divide above two equations,  given number of moles n and change in temperature dT is same  QVQP=CVCP=35  ⇒QV=35ΔQP given QP=210 joule QV=35x210=126J=heat required to raise the temperature of gas through 10K, at constant volume