500 gm ice at 0ºC is added in 2000 gm water at tºC. If the final temperature of system is 0ºC, then the value of 't' is (latent heat of fusion of ice =80 cal/gm and specific heat capacity of water= 1 cal/gm-ºC)

 

2 moles of an ideal gas absorbs 720 cal heat when heated from 27ºC to 87ºC, at constant volume. 'Cp/Cv' for the gas is :

 

Five moles of a monoatomic ideal gas is heated from 300 K to 400 K at constant pressure. The amount of heat absorbed is :