What mass of water can be heated by 40 C, transferring 4.5 kJ of heat to it?

The amount of heat required to heat water can be calculated using the formula:

Q = C * m * ∆t, where Q is the amount of heat expended on heating (Q = 4.5 kJ = 4500 J), C is the specific heat capacity of water (C = 4200 J / (kg * K)), m is the required mass of water (kg), ∆t – change in water temperature (∆t = 40 ºС).

Let us express and calculate the mass of heated water:

m = Q / (C * ∆t) = 4500 / (4200 * 40) = 0.0268 kg = 26.8 g.

Answer: You can heat 26.8 g of water.