250 g of water at
30∘C is contained 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.
Given : specific latent heat of fusion of ice = 336×103Jkg−1, specific heat capacity of copper = 400Jkg−1K−1, specific heat capacity of water = 4200Jkg−1K−1 :