140 calories of heat is required to raise the temperature of 2 moles of an ideal diatomic gas at constant pressure from 0° C to 10°C. How much heat is required to heat it through same range at constant volume?

detailed solution

Correct option is B

amount of heat required to raise temperature of gas at constant pressure is given bydQp=nCpdTdQp=140 calories (given)n=number of moles=2  (given)Cp=specific heat at constant pressure dT=change in temperature=10-0=100Csubstitute given values in the above formula140=2Cp(10)⇒Cp=7γ=CpCv=1.4(given)substitute Cp value in above equation,  we get Cv=5amount of heat required to raise temperature of gas at constant volume is given by dQv=nCvdT=2(5)10=100 calorie