Name _______________________________________________________
Period ________________
Lab Partners: __________________________________________________Date submitted___________________
Lab 3.11 Boiling Point
Purpose: Use boiling point as a characteristic property to identify an unknown liquid.
Hypothesis:
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Rationale:
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Materials:
Safety glasses
Pegboard
Fire stand and burner
Large test tube
Small test tube
Two holed rubber stopper with tubing and
thermometer
Boiling Chips
Stop watch
2 Clamps
Beaker (250ml)
Safety: Safety goggles, proper handling of chemicals and glassware
 Draw a labeled diagram of the apparatus
Procedure: (see page 59 in text)
1. Set up apparatus as shown in Figure 3.7 on page 59. Make sure the thermometer touches water only and
not glass, and that it is completely submerged. Add 1-2 boiling chips to prevent uneven boiling.
2. Adjust the thermometer in the test tube so that you can read it at the cork’s slit.
3. Heat the liquid in the test tube and record the temperature every half-minute until the liquid has been
boiling for about 5 minutes.
4. On your data table, highlight or mark with an asterisk the temperature of the liquid just as it begins to
boil.
5. Plot a graph of the temperature of the liquid as a function of time.
Lab Group Data
TIME
MIN
C
SUBS.
Class Boiling Point Data
TIME
MIN
C
SUBS.
TIME
MIN
0
10
20
0.5
10.5
20.5
1
11
21
1.5
11.5
21.5
2
12
22
2.5
12.5
22.5
3
13
23
3.5
13.5
23.5
4
14
24
4.5
14.5
24.5
5
15
25
5.5
15.5
25.5
6
16
26
6.5
16.5
26.5
7
17
27
7.5
17.5
27.5
8
18
28
8.5
18.5
28.5
9
19
29
9.5
19.5
29.5
C
SUBS.
Substance A
(C)
Vol
(mL)
Substance B
(C)
Sample________
Sample Volume __________
Boiling Point
__________
Vol
(mL)
Do all the graphs look alike at the beginning of the curve?
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Do all the graphs have a flat section?
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Did the other teams with the same liquid get the same boiling temperature?
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What does a difference in boiling point reveal?
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Does the boiling point of a liquid depend on the amount of liquid?
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Conclusion: Is boiling point a characteristic property? Use evidence to explain your answer.
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