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 R=8.31 J/mol⋅K ) [2012]
a. 62 J
b. 104 J
c. 124 J
d. 208 J