Question

The constants for H2O are shown here: Specific heat of ice: sice=2.09 J/(g⋅∘C) Specific heat of liquid water: swater=4.18 J/(g⋅∘C) Enthalpy of fusion (H2O(s)→H2O(l)): ΔHfus=334 J/g Enthalpy of vaporization (H2O(l)→H2O(g)): ΔHvap=2250 J/g

Part A How much heat energy, in kilojoules, is required to convert 73.0 g of ice at −18.0 ∘C to water at 25.0 ∘C ? Express your answer to three significant figures and include the appropriate units.

6.56 kJ is incorrect.

Answer 1

The conversion of ice to steam takes place as ice(s)ice(s)- 2 water (/) 3water (l -18°C 0°C 0°C 25°C Calculate the heat energy required for the first phase change from -18°C to 0°Q Here, m is the mass, C is the specific heat, and AT is the temperature change (T,-71) q,-73,0 gx209 J/(g·°C)×(0 °C-(-18°C)) 2746.26J 2. Calculate the heat energy required for the second phase change from 0°C to 0°C fus 73.0 gx334 J/g -24382 J Calculate the heat energy required for the third phase change from 0°C to 25°C. 73.0 gx4.18 J/g °Cx(25 °C -(0 °c)) 7628.5 J Thus, add all these energies to calcul ate the heat energy required to convert ice at 18°C to water at 25°C Total heat energy -g+a2 +43 = 2746.26 J+ 24382 J+7628.5 J 1 kJ 3475676 JX10 34.7 kJ