How much energy (in JJ) is lost when a sample of iron with a mass of 29.2 gg cools from 79.0 ∘C∘C to 27.0 ∘C∘C?

- 0.674 kJ.

Explanation:

The equation used to solve this problem is:

Q = mCΔT

where,

Q = amount of heat

m = mass of the substance

C = specific heat capacity

ΔT = change in temperature

= Temp. f - Temp. i

Given:

m = 29.2 g

Temp. i = 79°C

Temp. f = 27°C

Cp (iron) = 0.444 J/g. K

Q = mCΔT

ΔT = 27.0°C - 79.0°C

= - 52°C

= 29.2 * 0.444 * - 52

Q = - 674.17 J

= 0.674 kJ.