2 Kg of ice at -20 degree C is diverse with 5Kg of water 20 degree C in an insulating vessel having negligible heat capacity. Measure the final mass of water remaining in the container. It is given that the particular heats of water and ice are 1Kcal/kg/degree C and 0.5Kcal/kg/degree C whereas latent heat of fusion of ice is 80 kcal/kg

Ans)  apply the formula of mcT and at first measure the amount of heat losed by water at 0 degree.

The calculate the amount of heat gained by ice to go to 0 degree.

Now subtract the second from the first to get heat left for absorption.

Equate this heat to (mL)=latent heat ...and get the mass of  new water produced.

You will get it as 1 kg.

Hence the  5+1=6 kg