A container filled with 2.46 kg of water underwent a temperature change from 25.24 °C to 27.31 °C. How much heat, measured in kilojoules, did the water absorb?

The correct answer is 21.3 J

Explanation:

The heat absorbed by water can be calculated by using the following equation:

heat = m x Sh x ΔT

Where m is the mass of water (2.46 kg = 2460 g), Sh is the specific heat capacity of water (4.18 J/g.ºC) and ΔT is the difference of temperatures (final T - initial T). We introduce this values and calculate the heat:

heat=2460 g x 4.18 J/g.ºC x (27.31ºC - 25.24ºC)

heat = 21,285.39 J

As 1 KJ = 1000 J, we must divide the answer into 1000 to obtain the heat in KJ:

21,285.39 J x 1 KJ/1000 J = 21.28 KJ≅ 21.3 KJ