Determining Freezing Points Lab
Materials
1) (4) goggles
2) large test-tubes filed with candle wax (C25H52) - obtain from teacher
3) test-tube tongs
4) test-tube rack
5) thermometer
6) timer
Directions
1) Use the test tube tongs to obtain a test tube filled with liquid candle wax (C25H52).
Use caution as the candle wax (C25H52) will be hot. Place the test tube in the testtube rack.
2) Use the wire loop stirrer and stir the liquid to make sure that it is the same
temperature throughout (if the candle wax (C25H52) appears to be a liquid you do
not need to stir it).
3) Place the thermometer into the liquid candle wax (C25H52) and record the initial
temperature in box ‘A’. Hold the thermometer so that it does not touch the sides
of the test tubes. Leave the thermometer in the test-tube for the entire experiment.
4) Wait until the liquid in the thermometer has stopped rising. Record this
temperature in box ‘B’.
5) Start the timer.
6) Continue recording the temperature of the liquid candle wax (C25H52) every
minute until it has formed a solid. Use box ‘C’ – ‘AC’.
7) Record the temperature the candle wax (C25H52) became a solid (box ‘AD’) and
indicate how many minutes that took (BOX ‘AE’).
8) Graph your results. Indicate at what point the liquid became a solid.
Problem / Question (what are you trying to solve)
Data
Time (Minutes)
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
10.0
11.0
12.0
13.0
14.0
15.0
16.0
17.0
18.0
19.0
20.0
21.0
22.0
23.0
24.0
25.0
26.0
27.0
28.0
Temperature (o C)
A)
B)
C)
D)
E)
F)
G)
H)
I)
J)
K)
L)
M)
N)
O)
P)
Q)
R)
S)
T)
U)
V)
W)
X)
Y)
Z)
AA)
AB)
AC)
State of Matter (solid/liquid)
Temperature candle wax (C25H52)
became a solid (oC).
AD
Time required for candle wax
(C25H52) to become a solid (minutes).
AE
Questions (answer in a complete sentence)
1) How does the freezing point of candle wax (C25H52) compare to the
freezing point of water (H2O)?
2) What happened to the energy of the molecules as the candle wax
(C25H52) became a solid?
3) Based upon your observations infer the melting point of candle wax
(C25H52).
4) How is the freezing point different from the melting point?