Thermochemistry Lab
Heat of Fusion of Ice (Hfusion) Lab
Pure substances have characteristic melting and freezing behavior. Pure water
changes from a solid (ice) at 0o C as energy is added to it. In this experiment you
will determine the energy required to melt one gram of ice by letting an excess of
it interact with warm water in a Styrofoam cup (ice calorimeter). The ice will cool
the water to about 0oC. The energy given up by the water as it cools is the
energy used to melt the ice.
Heat lost by warm water = Heat gained by ice
q = mwater x Cpwater xT
q= mice x Hfusion
(Cpwater = 4.18J/g)
Procedure:
1.Mass a dry styrofoam cup. Record.
2.Measure 100.0 ml of warm water into a styrofoam cup. Mass and record.
3.Measure and record the temperature of the water.
4.Obtain 2-3 ice cubes. Shake excess water from them. Stir gently with the
stirring rod. Before the ice is completely melted.
5.Continue adding ice cubes one at a time until the temperature is about
o
0 C and temperature remains the same for a period of time. Record the lowest
temperature reached.
6.Carefully pull out the remaining ice cubes, allow the water to drip back into
the cup. Mass and record.
Data Table: (Use this data table during lab, copy all data on separate sheet)
A. Mass of empty styrofoam cup ______________________g
B. Mass of water + cup _____________________________g
C. Mass of water (mwater)_____________________________g
D. Mass of water+melted ice+cup _____________________g
E. Mass of melted ice (mice)______________________________g
F. Initial temperature of water _________________________ oC
G. Final temperature of water +melted ice________________ oC
H. Temperature change (T) = G – F ____________________oC
I. Heat lost by warm water = q = mwater x Cpwater xT
q = ___________________________J
J. Heat gained by ice = mice x Hfusion = ______________________J
Heat lost by warm water = Heat gained by ice
K. q = mwater x Cpwater xT
q= mice x Hfusion
L. Heat of fusion of ice : Hfusion = mwater x Cpwater xT J/g
mice
M. Determine the number of KJ required to melt 1 mole of ice.
Hfusion = ________________________________KJ/mole
N. Rewrite chemical equation for this reaction using energy term in the equation.
O. Calculate % error for this experiment.
P. Is the reaction endothermic or exothermic or both? Explain.