A 1.8 kg block of iron at 27 ∘c is rapidly heated by a torch such that 18 kj is transferred to it. what temperature would the block of iron reach assuming the complete transfer of heat and no loss to the surroundings? if the same amount of heat was quickly transferred to a 850 g pellet of copper at 23 ∘c, what temperature would it reach before losing heat to the surroundings?

There can be two type of heat energy: sensible heat and latent heat. Sensible heat is the heat added or remove to change the temperature of the substance. Latent heat is the heat added or removed at constant temperature when phase change occurs. In this case, we compute the sensible heat. Its equation is:

Heat energy = mCpΔT

where Cp is the specific heat of a specific substance. For iron, Cp = 0.444 J/g·°C. For copper, Cp = 0.385 J/g·°C.

Thus, the solutions and answers are as follows:

1.) 18,000 J = (1.8 kg) (444 J/kg·°C) (T - 27°C)

T = 49.52°C

2.) 18,000 J = (850 g) (0.385 J/g·°C) (T - 23°C)

T = 78°C