Final answer:
To melt the ice cube, we need to bring it from -8.0°C to 0°C and then provide the energy for the phase change from solid to liquid. The total energy required is 8590 J.
Step-by-step explanation:
To completely melt an ice cube, we need to provide the energy necessary for the phase change from solid to liquid. First, we need to bring the ice cube from -8.0˚C to 0˚C. The energy required for this temperature change can be calculated using the heat capacity of solid water, which is given as 1.20 J/g°C.
Energy = mass x heat capacity x temperature change
Energy = 25 g x 1.20 J/g°C x (0°C - (-8.0°C))
Energy = 25 g x 1.20 J/g°C x 8.0°C
Energy = 240 J
Next, we need to provide the energy for the phase change. The heat of fusion (Hf) for solid water is given as 334 J/g.
Energy for phase change = mass x heat of fusion
Energy for phase change = 25 g x 334 J/g
Energy for phase change = 8350 J
Therefore, the total energy required to completely melt the ice cube is 240 J + 8350 J = 8590 J.