Question

How much heat is required to change a 48.4 g ice cube from ice at -11.5°C to water at 72°C? (if necessary, use cice=2090 J/kg°C and csteam= 2010 J/kg°C)

How much heat is required to change a 48.4 g ice cube from ice at -11.5°C to steam at 116°C?

Answer 1

a) The heat needed is the sum of the following terms:
Qneeded = heat to reach melting point + heat to melt + heat to reach melting point 63 C

Thus we have
Qneeded = 0.0484 [2090*11.5 + 3.33*10^5 + 4186*72]
= 31867.86J

b)
Qneeded = heat to reach melting point + heat to melt + heat to reach melting point 72 C+ heat to vaporize + heat to reach 116 C

Thus we have
Qneeded = 0.0484 [2090*11.5 + 3.33*10^5 + 4186*100 + 2.26*10^6 + 2010*15 ]
= 148383.994 J
= 1.483 * 10^5 J