Two moles of ideal helium gas are in a rubber balloon at 30 °C. The balloon is fully expandable and can be assumed to require no energy in its expansion. The temperature of the gas in the balloon is slowly changed to 35 °C. The amount of heat required in raising the temperature is nearly (take J/mol.K)
← IIT-JEE 2012 · Paper 2
PhysicsSingle correct+3 / -1Question 5 of 60
IIT-JEE 2012 · Paper 2, Physics question 5
Answer and worked solution
Official answer: D
Process. A freely expanding balloon keeps the gas at atmospheric pressure, so the heating is at constant pressure.
Heat. Helium is monatomic, :
(D)