Lab Report
Final Report
Exercise 1
Data Table 1: Dialysis Tubing Results
CHEM 182 DL1 Colligative Propert ies and Osmotic Pressure
The light corn syrup in the dialysis tubing is hypotonic to the water because it increased in mass over the amount of time.
1. In your experiment, is the light corn syrup in the dialysis tubing hypertonic or hypotonic to the water?
The molar mass of the antibiotic is 7.47 x 102 g/mol. This is because: 23.6 C = 296.75 K. 8.34 mm Hg x 1/760 mm Hg = .0197 atm. .0197 atm = M x (.0821 (L)(atm) / (mol)(K)) x 296.75 K. .0197 atm / 24.36 (L)(atm) / (mol). M = .0197 atm / 24.36 x (mol-1)(atm). M + 8.09 x 10-4mol/L. .604 g / 8.09 x 10-4mol = g / 1 mol = 7.46 x 102g/mol.
2. 0.302 grams of an antibiotic was dissolved in enough water at 23.6°C to make 500.0 mL of solution. T he solution has an osmotic pressure of 8.34 mm Hg. What is the molar mass of the antibiotic? Show your work.
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Exercise 2
Data Table 2: Temperature Readings for Freezing Point
Time Mass of Dialysis Tubing and Contents
0 minutes
30 minutes
60 minutes
17.2g
20.9g
25.2g
The three freezing points all differ. The first was 2, the second 0, and the third -2. I think there is relationship between the amount of solute in the solution and the freezing temperatures because each started at a lower temperature than the one before and they dropped and ended at a lower freezing point than the one before.
1. Describe the three f reezing points. Is there a relationship between the amount of solute in the solution and the f reezing temperature?
Some practical applications of freezing point depression are antifreeze for example, used in car radiators. Also, salt, when it is used on ice in winter.
2. What are some practical applications of f reezing point depression?
Time (seconds) Temp (°C) of Control (tap water)
30
60
90
4
3
3
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120
150
180
210
240
270
300
330
360
390
420
450
480
510
540
570
600
Time (seconds) Temp (°C) of Solution +0.5 tsp (~2.5 mL) salt
30
60
3
2
2
1
1
1
1
1
1
1
1
1
1
1
0
0
0
2
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90
120
150
180
210
240
270
300
330
360
390
420
450
480
510
540
570
600
Time (seconds) Temp (°C) of Solution +1.0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
0
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tsp (~5 mL) salt
30
60
90
120
150
180
210
240
270
300
330
360
390
420
450
480
510
540
570
0
0
-1
-1
-1
-2
-2
-2
-2
-2
-2
-2
-2
-2
-2
-2
-2
-2
-2
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Graph 1: Freezing Point Depression of Salt Solutions
Exercise 3
600 -2
The three boiling points were quite close. I think there is a relationship between the amount of solute in the solution and the boiling temperature because the more solute, the higher the boiling points were.
1. Compare the three boiling points. Is there a relationship between the amount of solute in the solution and the boiling temperature?
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Data Table 3: Temperature Readings for Boiling Point
Some practical applications of the boiling point elevation are when ethylene glycol is added to increase the boiling point of a solution or when we use salt in the water when we cook in order to make the food boil quicker.
2. What are some practical applications of boiling point elevation?
Temp (°C) of Control (tap water)
Temperature at Rolling Boil
Temp (°C) of Solution +0.5 tsp (~2.5 mL) salt
Temperature at Rolling Boil
Temp (°C) of Solution +1.0 tsp (~5 mL) salt
Temperature at Rolling Boil
101 ºC
104 ºC
106 ºC