Question

How much heat energy is required to change 2 kg of ice at 0c into water at 20c?

Answer 1

Answer:

200 kcal or 0.83 MJ

Explanation:

ICE (0 C) ----------- WATER (0 C) ---------- WATER (20 C)

Energy required to change ice to water = mL

                                                                  = 2000 g * 80 calories/g

                                                                  =160 kcal

Energy required to change water at 0 C to 20 C = ms(T-t)

                                                                                = 2000 g * 1 cal/g * (20-0 C)

                                                                                = 40 kcal

Total Energy required = 160 kcal + 40 kcal = 200 kilo calories or 0.83 MJ