Four moels of a perfect gas is heated to increase its temperature by 2^(0)C absorbsheat of 40 cal at constant volume. If the same gas is heated at constant pressure find the amount of heat supplied. (R = 2 cal/molK).

Four moels of a perfect gas is heated to increase its temperature by 2

1.	Four moels of a perfect gas is heated to increase its temperature by 2^(0)C absorbsheat of 40 cal at constant volume. If the same gas is heated at constant pressure find the amount of heat supplied. (R = 2 cal/molK).
Answer» Solution :Number of moles n = 4 Change in TEMPERATURE`Deltat=2` Heat ENERGY absorbed `dQ=40` cal. GAS constant `R = 2` cal/mole K Heat energy absorbed at constant pressure `dQ = dU +dW` per mole per kelvin. But `dU = C_(v)DT and dW = P dV` `C_(p)=C_(v) +R`Multiply with n.dT `nC_(p)dT=nC_(v)dT +nRdT` `nC_(p)dT =` Heat energyabsorbed at constant pressure by n moles of gas. `nC_(v)dT=dU =`Heat energy absorbed at constant volume. `:.dQ=dU+nRdT =40+4xx2xx2=56`cal Heat energy absorbed at constant presure when 4 moles of air is heated through `2^(0)=56`cal.