How much thermal energy must be added to a 87.5 g sample of ice at -25oC completely melt the entire sample? As part of your work, sketch a labelled heating curve. Circle the portion of the curve that is the focus of this question.

4.6 kJ

Explanation:

The energy required to raise the temperature of a substance from its initial temperature to a final temperature is given by:

Q = mcΔT

Where Q = energy, c = specific heat capacity of substance and ΔT = final temperature - initial temperature

Given that:

c = 2.1 kJ/kg°C, m = 87.5 = 0.0875 kg, ΔT = final temperature - initial temperature  = 0 - (-25) = 25

Q = 0.0875 * 2.1 *25

Q = 4.6 kJ