Calculate the energy needed to heat 4 kg of water from 25°c to 45°c.

heat =

80 kcal
100 kcal
180 kcal
280 kcal

(1 cal/g °C) x (4000 g) x (45 - 25)°C = 80000 cal = 80 kcal. So the answer is 80 kcal .

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