Question

Calculate the number of kilojoules to warm 125 g of iron from 23.5°C to 78.0°C.

Answer 1

3065.63 Kj, the specific heat of iron is .45

Answer 2

Q = 3.06 kJ

Solution:

The equation used for this problem is as follow,

Q = m Cp ΔT ----- (1)

Where;

Q = Heat = ?

m = mass = 125 g

Cp = Specific Heat Capacity = 0.450 J.g⁻¹.°C⁻¹

ΔT = Change in Temperature = 78.0 °C - 23.5 °C = 54.5 °C

Putting values in eq. 1,

Q = 125 g × 0.450 J.g⁻¹.°C⁻¹ × 54.5 °C

Q = 3065 J

Or,

Q = 3.06 kJ