Question

The temperature of a sample of iron with a mass of 10.0 g changed from 50.4°C to 25.0°C with the release of 114 J of energy. What is the specific heat of iron?

Answer 1

c = 449 J kg⁻¹ K⁻¹

Explanation:

The equation needed to solve this problem is the specific heat capacity equation: `ΔQ = mc Δ θ`
Where the terms are as follows:
- ΔQ is heat energy transferred (in J)
- m is the mass (in kg)
- c is the specific heat capacity (in J kg⁻¹ K⁻¹)
- Δθ is the temperature chance (in K or ºC)

The only unit conversion necessary is for the mass: `10.0 g = 0.010 kg`

To solve for the specific heat rearrange the equation and substitute the values in.
`c = (ΔQ) / (m Δθ) = 114 / (0.010 × (50.4 - 25.0)) = 448.81…`

To 3 sig. figs c = 449 J kg⁻¹ K⁻¹