Pre-Lab & Procedure Summary
Evaporation and Intermolecular Forces
Step-by-Step Lab Procedure
Step
What to do
Notes / Reminders
1
Clamp 2 temperature probes to a stand.
Tips hang freely.
2
Put Probe 1 in liquid A, Probe 2 in liquid B.
See rounds table below.
3
Wait 45 seconds.
Probes need time to adjust.
4
Click Start on computer.
Logger Pro records.
5
Wait 15 seconds with probes still in liquids.
Records initial max temp t1.
6
At the same time, pull both probes out.
Do it quickly together.
7
Tape probes so tips extend 5 cm over table edge.
8
Wait until temperatures stop dropping and start rising.
9
Click Stop when both reached minimum.
10
Use Statistics button.
Shows t1 and t2.
11
Record t1, t2, and ∆T = t2 - t1.
∆T negative.
12
Dispose filter paper, reset probes.
13
Store Latest Run.
14
Predict ∆T for next liquids.
15
Repeat for each round.
Alcohols ~300 sec.
Rounds
Round
Probe 1
Probe 2
1
ethanol
1-propanol
2
1-butanol
n-pentane
3
methanol
n-hexane
Data Table
Substance
ethanol
1-propanol
1-butanol
n-pentane
methanol
t1 (C) max
t2 (C) min
∆T (C)
n-hexane
Lab partners: _____________________ Date: ____________