250 g of water at 30 °C is present in a copper vessel of mass 50 g. Calculate the mass of ice required to bring down the temperature of the vessel and its contents to 5 °C.
Specific latent heat of fusion of ice = 336 x 103 J kg-1 .
Specific heat capacity of copper vessel = 400 J kg-1 °C-1 .
Specific heat capacity of water = 4200 J kg-1 °C-1 .
