calculate the amount of heat

Question

Calculate the amount of heat in kilocalories to melt 60.0 g of ice at 0 ℃ and warm the liquid to 65 ℃. H_fus = 80. cal/g; H_vap = 540 cal/g; SH = 1.00 cal/g

Answer 1

Best to approach this problem in a step-wise manner.

Step 1: melt 60 g ice @ 0º. q = m∆Hfus = (60.0 g )(80 cal / g) = 4800 cal

Step 2: raise temp of 60 g of liquid from 0º to 65º. q = mC∆T = (60.0 g)(1.00 cal/gº)(65º) = 3900 cal

(note: the SH should be 1.00 cal/gº and not cal/g)

Step 3: Sum the calories and convert to kcal. 4800 cal + 3900 cal = 8700 cal x 1 kcal/1000 cal = 8.70 kcal