posted by Meder
Inside an insulated container, a 250-g ice cube
at 0°C is added to 200 g of water at 18°C.
(i) What is the final temperature of the system?
(ii) What is the remaining ice mass?
To melt all of the ice, 250g*80cal/g = 20,000 calories must be added. The already-liquid water can transfer only 200*18 = 3600 calories as it cools from 18 to 0 C. Therefore some of the ice remains at equilibrium. (i) The final temperature is 0 C.
(ii) Bringing all of the original liquid from 18C to 0C transfers 3600 cal to the ice. That is enough to melt 3600/80 = 45 g.
205 g of ice remains.