Final answer:
To melt a 25 g ice cube at -8.0ºC, 240 J is used to warm the ice to 0ºC, and 8350 J is needed to melt the ice, totaling 8590 J of energy required.
Step-by-step explanation:
To find out how much energy is required to completely melt a 25 g ice cube at –8.0ºC, we'll need to calculate the energy needed in two stages: first, warming the ice to 0ºC, and second, melting the ice at 0ºC. To raise the temperature of the ice, we use the formula ‘q=mcΔT’, where 'q' is the heat energy, 'm' is the mass, 'c' is the specific heat capacity, and ΔT is the change in temperature. The heat of fusion, 'Hf', will be used for the melting process.
First, let's warm up the ice from –8.0ºC to 0ºC:
q = mcΔT
= (25 g)(1.20 J/gºC)(8ºC)
= 240 J
Now, let's melt the ice at 0ºC:
q = mHf
= (25 g)(334 J/g)
= 8350 J
To find the total energy required, we sum the energy to warm the ice and the energy to melt the ice:
Total energy = energy to warm + energy to melt = 240 J + 8350 J
= 8590 J
Therefore, 8590 J of energy is required to completely melt the 25 g ice cube at –8.0ºC.