Suppose that 90 g of hot water at a temperature of 75 degrees C is poured into a cavity in a very large block of ice at 0 degrees C.

(a) What will be the final temperature of the water in the cavity?
(b) What mass of ice must melt in order for the water to cool down to the temperature found in Part (a)?

1 answer

(a) If the ice block is really "very large", not all of it melts, and the final temperature remains 0 C. You end up with a large pool of 0 C liquid water including melted ice) in the ice block.

(b) If mass M of original ice melts,
Heat lost by poured water = Heat gained by melted ice

90g*75C*1.00cal/g*C = M (g)*80 (cal/g)

Solve for M

M = 84.4 g