An 8.5g Ice Cube is placed into 255g water.

Calculate temperature change in water upon the complete melting of the ice. (Assume all the energy required to melt the ice comes from the water.)

We use heat balance between ice and water to calculate the temperature change upon melting. In this case,

mass ice * heat of vaporization = mass water * cp water * delta T water

heat of vaporization is equal to 80 cal / g

8.5 g * 80 cal / g = 255 g * 1 cal/g C * (delta T) delta T is thus equal to 2.67 C.