test tube (outlined in steps 1–4 of Activity 1).
Record the exact mass in Data Table 2.
2.
Label another weigh boat “benzoic acid.”
3.
Place the boat on the scale and tare it. Use a
clean spoon and weigh 0.4 g of benzoic acid.
Record the exact mass in Data Table 2.
4.
Add the 0.4 g of benzoic acid to the 3 g of
lauric acid in the test tube.
5.
Reheat the water to approximately 80 °C
6.
Repeat steps 5–17 outlined in Activity
1, and record the temperature every 30
seconds until the temperature remains
constant for four consecutive readings. This
will be the freezing point for the “lauric acid +
0.4 g benzoic acid” solution.
7.
Repeat Steps 1–5 using 3.0 g lauric acid and
0.5 g benzoic acid.
Disposal and Cleanup
1.
Dispose of the weigh boats, spoons, and test
tubes with their contents in the trash.
2. Do not pour the warm lauric acid and
benzoic acid down the drain of the sink. It
will solidify and clog the pipe.
3.
Rinse and dry the 250-mL beaker and
thermometer. Return the thermometer to its
holder.
4.
Clean and sanitize the workspace.
7
ACTIVITY
8
Carolina Distance Learning
Time
(minutes)
Pure Lauric Acid
Lauric Acid + 0.4 g
Benzoic Acid
Lauric Acid + 0.5 g
Benzoic Acid
0.0
65.0
65.0
65.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
6.5
7.0
7.5
8.0
8.5
9.0
9.5
10.0
Temperature (°C)
Data Table 1: Cooling Data for Activities 1 and 2
continued on next page
