APSU Kinetic Study of A Bleach Reaction Post Lab Discussion

Write a post lab discussion on the kinetic study of a bleach reaction. I will attach everything needed

Austin Peay State University Department of Chemistry
Chem 1121
Kinetic Study of a Bleach Reaction
Cautions
These solutions may be toxic, irritants and corrosive. Avoid skin contact from all chemicals and wash thoroughly
if contact occurs.
Introduction
Kinetics is the area of chemistry that deals with the studying of the rates of reactions. Chemical processes
proceed at different rates, based on a number of variables. For example, the rusting of iron is a reasonably slow reaction
while the decomposition of TNT is an extremely fast reaction. Four main factors that control the rates of homogeneous
reactions in solution are: the nature of the reactants, the concentration of the reactants, the temperature at which the
reaction occurs, and the use of catalysts. Reactions will only occur when reactant molecules have enough energy to
interact or collide with other reactant molecules. Each one of the factors above affects how reactant molecules interact or
collide with each other.
Consider the general reaction scheme:
A+B→C+D
The official “rate” of the reaction can be determined by observing the rate at which the reactants A and B disappear or the
rate at which the products C and D appear. Experimentally, the change in concentration of A, B, C, and D with time can
be measured.
The instantaneous rate of reaction is expressed mathematically as follows:
𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅 𝑜𝑜𝑜𝑜 𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷 𝑜𝑜𝑜𝑜 𝐴𝐴 =
𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅 𝑜𝑜𝑜𝑜 𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴 𝑜𝑜𝑜𝑜 𝐶𝐶 =
𝐶𝐶ℎ𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎 𝑖𝑖𝑖𝑖 𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶 𝑜𝑜𝑜𝑜 𝐴𝐴
𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇 𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅 𝑓𝑓𝑓𝑓𝑓𝑓 𝐶𝐶ℎ𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎
𝐶𝐶ℎ𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎 𝑖𝑖𝑖𝑖 𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶 𝑜𝑜𝑜𝑜 𝐶𝐶
𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇 𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅 𝑓𝑓𝑓𝑓𝑓𝑓 𝐶𝐶ℎ𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎
These instantaneous rates are the same. There is only one true “rate” for a reaction.
=
=
−∆[𝐴𝐴]
∆𝑡𝑡
+∆[𝐶𝐶]
∆𝑡𝑡
(1a)
(1b)
The rate law expression for the general reaction scheme is given as “ rate = k [ A]x [B ]y ”. In the expression [A] and
[B] are the molar concentrations of the chemical species, A and B, x and y are the powers to which the respective
concentrations must be raised to describe the rate, and k is the specific rate constant.
One of the objectives of chemical kinetics is to determine the rate law. The orders of the reaction are the powers
to which the concentrations in the rate law are raised. Adding the individual exponents (x+y) together will give the overall
order of the reaction. One method for determining the order of the reaction is to observe how the concentration of a
reactant or product changes with time. The stoichiometry and order of the reaction have no dependence on each other
unless the reaction is a single step. Many if not most reactions we write are actually summaries of a multi-step reaction
mechanism and thus the stoichiometric coefficients and the rate law orders can be different. The specific rate constant, k,
has a definite value for a given reaction and is independent of the concentration and only depends on temperature and
the overall activation energy for the reaction.
The relationship between concentration and time varies with the order of the reaction and can be derived using
calculus from the rate law expression itself. For a reaction, A → P that follows first order kinetics with the rate law RATE =
k[A], the concentration time relationship is:
ln[𝐴𝐴] = −𝑘𝑘𝑘𝑘 + ln[ 𝐴𝐴0 ]
Revision F8
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Page 1 of 4
Austin Peay State University Department of Chemistry
CHEM 1121
Kinetic Study of a Bleach Reaction
If this same reaction follows 2nd order kinetics with the rate law RATE = k[A]2, the concentration time relationship is:
1
[𝐴𝐴]
= 𝑘𝑘𝑘𝑘 +
1
(3)
[𝐴𝐴0 ]
where A0 is the initial concentration, A is the concentration at a specified time, t is time, and k is the specific rate law
constant. These two equations are known as the integrated rate laws.
Graphical methods for determining the rate dependence of a single reactant were developed based on these
concentration-time relationships. For a reactant having a first order dependence, a plot of ln[A] vs time should be linear,
based on the equation:
ln[𝐴𝐴𝑡𝑡 ] = −𝑘𝑘𝑘𝑘 + 𝑙𝑙𝑙𝑙[𝐴𝐴0 ]
𝑦𝑦 = 𝑚𝑚𝑚𝑚 + 𝑏𝑏
(4a)
(4b)
If the reactant has second order dependence, a plot of 1/[A] vs time will be linear, based on the equation:
1
[𝐴𝐴𝑡𝑡 ]
= 𝑘𝑘𝑘𝑘 +
1
[𝐴𝐴0 ]
𝑦𝑦 = 𝑚𝑚𝑚𝑚 + 𝑏𝑏
(5a)
(5b)
The data is graphed both ways and curve fitted to the best straight line. For each graph the value of the correlation
coefficient (R2) is compared. The graph which has a R2 value that is closer to one is the better fit for the data and
determines the order of the reaction. In addition, the slope of the lines obtained can be used to calculate the specific rate
law constant for the reaction.
In today’s experiment, concentration-time data will be collected for the reaction between bleach and FD&C blue
food dye #1 to determine the order of the reaction with respect to food dye. Visible spectrometry will be used to measure
the absorbance of light by the blue food dye in the solution. If the solution is fairly dilute, Beer’s law (A = εbc) may be
used to determine the concentration at all times. As the reaction proceeds, the dye changes from blue to colorless. The
true rate law takes the form of:
Rate = k [dye]x [bleach]y
(6)
Keeping the bleach concentration large compared to the dye effectively “isolates” the dye, removing bleach from the rate
law. The order “x” of the reaction with respect to the dye as well as a “pseudo” rate constant will be obtained (the pseudo
rate constant is equal to k[bleach]y).
Four separate trials will be run, two using the stock dye solution as prepared, and two using a dilution of this stock
dye solution. If the initial bleach concentration remains the same in all trials and is large compared to the food dye
concentration, the rate constant should be the same (within experimental error) for all trials.
Revision S21
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Austin Peay State University Department of Chemistry
CHEM 1121
Kinetic Study of a Bleach Reaction
Procedure
1. Follow the LoggerPro “Colorimeter Calibration”
instructions.
2. Follow the LoggerPro “Experiment Set-up” instructions.
3. Obtain approximately 50 mL of stock food dye solution in
a 100 mL beaker. In a graduated cylinder, obtain
approximately 5 mL of bleach.
4. Obtain a 25 mL graduated cylinder. Add 10 mL of stock
food dye solution to this cylinder. Working quickly, add 1
mL of bleach, swirl the solution, quickly transfer the
solution to a cuvette and place in the colorimeter. Click
the green “Collect” button. Allow data to collect for at least
200 seconds.
5. Examine the graph of absorbance vs. time, making sure a
gradual decrease in absorbance is observed. Follow the
LoggerPro “Storing Your Results” instructions.
6. Rinse all glassware used and repeat steps 5 and 6 once
more using stock food dye.
7. Rinse the glassware again, and this time, add 5 mL of stock food dye solution and 5 mL of deionized water to the
graduated cylinder. Working quickly, add 1 mL of bleach, swirl the solution, quickly transfer the solution to a
cuvette and place in the colorimeter. Click the green “Collect” button. Allow data to collect for at least 200
seconds.
8. Examine the graph of absorbance vs. time, making sure a gradual decrease in absorbance is observed. Follow
the LoggerPro “Storing Your Results” instructions.
9. Rinse all glassware used and repeat steps 7 and 8 once more.
Disposal
Dispose of all solutions down the sink and flush with an excess of water.
Clean-Up
Wash all glassware with soap then rinse 3 times with tap water, and once with deionized water.
Clean your work area with water and dry with paper towels. Wash your hands before leaving the laboratory.
Revision S21
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Austin Peay State University Department of Chemistry
CHEM 1121
Kinetic Study of a Bleach Reaction
Data Sheet
Data Analysis
1. For EACH trial, use Excel to prepare three graphs, and obtain a linear best fit equation and R2 value. All of these
charts assume the bleach is in excess for all reactions performed.
a. Zero order rate law graph: plot absorbance vs. time.
b. First order rate law graph: plot ln(Abs) vs time.
c.
2.
Second order rate law graph: plot 1/Abs vs time.
For EACH trial, use the R2 value to determine which graph is most linear. This is the order of the reaction with
respect to food dye. Write a rate law for the reaction using the format: Rate = k[dye]x to write a rate law for the
reaction. [dye] denotes the molar concentration of the food dye solution. Substitute the appropriate digit for the
value of x in the rate law based on the determined R2 values.
3. Based on the rate law and graphs, determine is the value of k, the rate constant for each trial. Include units.
Finally, calculate an average k.
4. In the post-lab, state whether the reaction order and rate law constants should be the same across all trials
performed, explaining the reasoning.
Revision S21
Page 4 of 4
(A)
0.6
0.5
0.4
Absorbance
1/(A)
1.76929792
1.86293661
1.95878239
2.06566457
2.17341492
2.29009483
2.41199949
2.54797416
2.68933236
2.83458458
3.00060563
3.16480199
3.33765841
3.52377391
3.72146003
3.91565581
4.13631881
4.36742441
4.60380253
4.85093716
5.11461836
0.3
0.2
0.1
0
0
10
20
30
ln(A)
0
-0.2
0
10
20
30
-0.4
Absorbance
TRIAL 1
ln(A)
-0.5705828
-0.6221541
-0.6723231
-0.725452
-0.7762996
-0.8285932
-0.8804561
-0.9352986
-0.989293
-1.0418954
-1.0988141
-1.1520905
-1.2052695
-1.2595325
-1.3141161
-1.3649828
-1.4198062
-1.4741735
-1.5268826
-1.5791719
-1.6321028
-0.6
-0.8
-1
-1.2
-1.4
-1.6
-1.8
1/(A)
6
5
Absorbance
Run 1: Time (s)(A)
0 0.56519594
3 0.53678692
6 0.51052123
9 0.4841057
12 0.46010543
15 0.43666314
18 0.41459379
21 0.39246866
24 0.3718395
27 0.35278538
30 0.33326605
33 0.31597553
36 0.29961125
39 0.28378665
42 0.26871174
45 0.25538506
48 0.24176086
51 0.2289679
54 0.21721175
57 0.20614573
60 0.19551801
4
3
2
1
1
0
0
10
20
30
Time
(A)
y = -0.0061x + 0.5343
R² = 0.9816
30
40
50
60
70
40
50
60
70
Time
ln(A)
30
y = -0.0178x – 0.5648
R² = 0.9999
Time
1/(A)
y = 0.0551x + 1.5057
R² = 0.9791
30
40
Time
50
60
70
(A)
0.25
0.2
Absorbance
1/(A)
4.7046929
5.02873552
5.37003785
5.74080663
6.14022376
6.50268768
6.90617304
7.25078811
7.63131434
8.03400605
8.48077934
8.82664242
9.17214353
9.46683059
9.82457729
10.1810107
10.5702436
10.858526
11.2033524
11.3629754
11.4473606
0.15
0.1
0.05
0
0
10
20
30
ln(A)
0
0
10
20
30
-0.5
Absorbance
TRIAL 2
ln(A)
-1.5485605
-1.6151686
-1.680835
-1.7475997
-1.8148612
-1.8722156
-1.9324157
-1.9811102
-2.0322601
-2.0836833
-2.1378023
-2.1777747
-2.216171
-2.2477942
-2.2848871
-2.3205243
-2.3580428
-2.3849506
-2.4162131
-2.4303603
-2.4377592
-1
-1.5
-2
-2.5
-3
1/(A)
14
12
Absorbance
Run 1: Time (s)(A)
0 0.21255372
3 0.19885715
6 0.18621843
9 0.17419155
12 0.16286051
15 0.15378257
18 0.14479799
21 0.13791604
24 0.13103903
27 0.1244709
30 0.11791369
33 0.11329336
36 0.10902577
39 0.10563197
42 0.10178555
45 0.09822208
48 0.0946052
51 0.09209353
54
0.089259
57 0.08800512
60 0.08735638
10
8
6
4
4
2
0
0
10
20
30
(A)
y = -0.002x + 0.1896
R² = 0.926
30
40
50
60
70
40
50
60
70
Time
ln(A)
30
y = -0.015x – 1.6307
R² = 0.9744
Time
1/(A)
y = 0.1187x + 4.7596
R² = 0.9964
30
40
Time
50
60
70
(A)
0.25
0.2
Absorbance
1/(A)
4.7046929
5.02873552
5.37003785
5.74080663
6.14022376
6.50268768
6.90617304
7.25078811
7.63131434
8.03400605
8.48077934
8.82664242
9.17214353
9.46683059
9.82457729
10.1810107
10.5702436
10.858526
11.2033524
11.3629754
11.4473606
0.15
0.1
0.05
0
0
10
20
30
ln(A)
0
0
10
20
30
-0.5
Absorbance
TRIAL 3
ln(A)
-1.5485605
-1.6151686
-1.680835
-1.7475997
-1.8148612
-1.8722156
-1.9324157
-1.9811102
-2.0322601
-2.0836833
-2.1378023
-2.1777747
-2.216171
-2.2477942
-2.2848871
-2.3205243
-2.3580428
-2.3849506
-2.4162131
-2.4303603
-2.4377592
-1
-1.5
-2
-2.5
-3
1/(A)
14
12
Absorbance
Run 1: Time (s)(A)
0 0.21255372
3 0.19885715
6 0.18621843
9 0.17419155
12 0.16286051
15 0.15378257
18 0.14479799
21 0.13791604
24 0.13103903
27 0.1244709
30 0.11791369
33 0.11329336
36 0.10902577
39 0.10563197
42 0.10178555
45 0.09822208
48 0.0946052
51 0.09209353
54
0.089259
57 0.08800512
60 0.08735638
10
8
6
4
4
2
0
0
10
20
30
Axis Title
(A)
y = -0.002x + 0.1896
R² = 0.926
30
40
50
60
70
50
60
70
Axis Title
ln(A)
30
40
y = -0.015x – 1.6307
R² = 0.9744
Axis Title
1/(A)
y = 0.1187x + 4.7596
R² = 0.9964
30
40
Axis Title
50
60
70
(A)
0.25
0.2
Absorbance
1/(A)
4.7046929
5.02873552
5.37003785
5.74080663
6.14022376
6.50268768
6.90617304
7.25078811
7.63131434
8.03400605
8.48077934
8.82664242
9.17214353
9.46683059
9.82457729
10.1810107
10.5702436
10.858526
11.2033524
11.3629754
11.4473606
0.15
0.1
0.05
0
0
10
20
30
ln(A)
0
0
10
20
30
-0.5
Absorbance
TRIAL 3
ln(A)
-1.5485605
-1.6151686
-1.680835
-1.7475997
-1.8148612
-1.8722156
-1.9324157
-1.9811102
-2.0322601
-2.0836833
-2.1378023
-2.1777747
-2.216171
-2.2477942
-2.2848871
-2.3205243
-2.3580428
-2.3849506
-2.4162131
-2.4303603
-2.4377592
-1
-1.5
-2
-2.5
-3
Time
1/(A)
14
12
Absorbance
Run 1: Time (s)(A)
0 0.21255372
3 0.19885715
6 0.18621843
9 0.17419155
12 0.16286051
15 0.15378257
18 0.14479799
21 0.13791604
24 0.13103903
27 0.1244709
30 0.11791369
33 0.11329336
36 0.10902577
39 0.10563197
42 0.10178555
45 0.09822208
48 0.0946052
51 0.09209353
54
0.089259
57 0.08800512
60 0.08735638
10
8
6
4
4
2
0
0
10
20
30
(A)
y = -0.002x + 0.1896
R² = 0.926
30
40
50
60
70
40
50
60
70
Time
ln(A)
30
y = -0.015x – 1.6307
R² = 0.9744
Time
1/(A)
y = 0.1187x + 4.7596
R² = 0.9964
30
40
Time
50
60
70
(A)
0,6
0,5
0,4
Axis Title
1/(A)
1,76929792
1,86293661
1,95878239
2,06566457
2,17341492
2,29009483
2,41199949
2,54797416
2,68933236
2,83458458
3,00060563
3,16480199
3,33765841
3,52377391
3,72146003
3,91565581
4,13631881
4,36742441
4,60380253
4,85093716
5,11461836
0,3
0,2
0,1
0
0
10
20
30
ln(A)
0
-0,2
0
10
20
30
-0,4
-0,6
Axis Title
TRIAL 1
ln(A)
-0,5705828
-0,6221541
-0,6723231
-0,725452
-0,7762996
-0,8285932
-0,8804561
-0,9352986
-0,989293
-1,0418954
-1,0988141
-1,1520905
-1,2052695
-1,2595325
-1,3141161
-1,3649828
-1,4198062
-1,4741735
-1,5268826
-1,5791719
-1,6321028
-0,8
-1
-1,2
-1,4
-1,6
-1,8
1/(A)
6
5
Axis Title
Run 1: Time (s)(A)
0 0,56519594
3 0,53678692
6 0,51052123
9 0,4841057
12 0,46010543
15 0,43666314
18 0,41459379
21 0,39246866
24 0,3718395
27 0,35278538
30 0,33326605
33 0,31597553
36 0,29961125
39 0,28378665
42 0,26871174
45 0,25538506
48 0,24176086
51 0,2289679
54 0,21721175
57 0,20614573
60 0,19551801
4
3
2
1
1
0
0
10
20
30
Axis Title
(A)
y = -0,0061x + 0,5343
R² = 0,9816
30
40
50
60
70
50
60
70
Axis Title
ln(A)
30
40
y = -0,0178x – 0,5648
R² = 0,9999
Axis Title
1/(A)
y = 0,0551x + 1,5057
R² = 0,9791
30
40
Axis Title
50
60
70
(A)
0,25
0,2
Axis Title
1/(A)
4,7046929
5,02873552
5,37003785
5,74080663
6,14022376
6,50268768
6,90617304
7,25078811
7,63131434
8,03400605
8,48077934
8,82664242
9,17214353
9,46683059
9,82457729
10,1810107
10,5702436
10,858526
11,2033524
11,3629754
11,4473606
0,15
0,1
0,05
0
0
10
20
30
ln(A)
0
0
10
20
30
-0,5
-1
Axis Title
TRIAL 2
ln(A)
-1,5485605
-1,6151686
-1,680835
-1,7475997
-1,8148612
-1,8722156
-1,9324157
-1,9811102
-2,0322601
-2,0836833
-2,1378023
-2,1777747
-2,216171
-2,2477942
-2,2848871
-2,3205243
-2,3580428
-2,3849506
-2,4162131
-2,4303603
-2,4377592
-1,5
-2
-2,5
-3
1/(A)
14
12
10
Axis Title
Run 1: Time (s)(A)
0 0,21255372
3 0,19885715
6 0,18621843
9 0,17419155
12 0,16286051
15 0,15378257
18 0,14479799
21 0,13791604
24 0,13103903
27 0,1244709
30 0,11791369
33 0,11329336
36 0,10902577
39 0,10563197
42 0,10178555
45 0,09822208
48 0,0946052
51 0,09209353
54
0,089259
57 0,08800512
60 0,08735638
8
6
4
4
2
0
0
10
20
30
Axis Title
(A)
y = -0,002x + 0,1896
R² = 0,926
30
40
50
60
70
50
60
70
Axis Title
ln(A)
30
40
y = -0,015x – 1,6307
R² = 0,9744
Axis Title
1/(A)
y = 0,1187x + 4,7596
R² = 0,9964
30
40
Axis Title
50
60
70
(A)
0,45
0,4
0,35
Axis Title
1/(A)
2,45824186
2,53466054
2,62196574
2,70323539
2,78522739
2,87764407
2,97340129
3,06799207
3,1661763
3,26839486
3,37834514
3,48208272
3,59082473
3,71368216
3,82617775
3,95275027
4,07481129
4,19023493
4,32309275
4,45056297
4,57318593
0,3
0,25
0,2
0,15
0,1
0,05
0
0
10
20
30
ln(A)
0
-0,2
0
10
20
30
-0,4
-0,6
Axis Title
TRIAL 3
ln(A)
-0,8994464
-0,9300597
-0,9639243
-0,9944493
-1,0243295
-1,0569719
-1,0897065
-1,1210233
-1,1525246
-1,184299
-1,217386
-1,2476306
-1,2783819
-1,3120239
-1,3418663
-1,3744116
-1,4048244
-1,4327568
-1,4639711
-1,4930306
-1,5202101
-0,8
-1
-1,2
-1,4
-1,6
-1,8
1/(A)
Axis Title
Run 1: Time (s)(A)
0 0,4067948
3 0,39453015
6 0,38139324
9 0,36992709
12 0,35903711
15 0,34750649
18 0,33631518
21 0,32594608
24 0,31583838
27 0,30596058
30 0,29600291
33 0,28718445
36 0,27848756
39 0,26927453
42 0,26135743
45 0,25298841
48 0,24541014
51 0,2386501
54 0,23131588
57 0,22469068
60 0,21866594
5
4,5
4
3,5
3
2,5
2
1,5
1
1,5
1
0,5
0
0
10
20
30
Axis Title
(A)
y = -0,0031x + 0,3964
R² = 0,9913
30
40
50
60
70
50
60
70
Axis Title
ln(A)
30
40
y = -0,0104x – 0,9013
R² = 0,9998
Axis Title
1/(A)
y = 0,0355x + 2,3651
R² = 0,9947
30
40
Axis Title
50
60
70
(A)
Axis Title
1/(A)
5,40373544
5,55383182
5,70003601
5,87513751
6,02515707
6,1856757
6,36482046
6,55320249
6,71591271
6,84238814
7,03415815
7,19508434
7,38409546
7,5728046
7,76139352
7,92382086
8,07651719
8,28811667
8,47542262
8,68503859
8,88054038
0,2
0,18
0,16
0,14
0,12
0,1
0,08
0,06
0,04
0,02
0
0
10
20
30
ln(A)
0
0
10
20
30
-0,5
Axis Title
TRIAL 4
ln(A)
-1,6870905
-1,7144881
-1,7404725
-1,7707295
-1,7959435
-1,8222362
-1,850786
-1,8799539
-1,9044797
-1,9231368
-1,950778
-1,9733981
-1,9993284
-2,0245635
-2,0491619
-2,0698735
-2,0889607
-2,1148228
-2,1371705
-2,1616018
-2,1838624
-1
-1,5
-2
-2,5
1/(A)
Axis Title
Run 1: Time (s)(A)
0 0,18505717
3 0,18005587
6 0,17543749
9 0,17020878
12 0,16597078
15 0,16166383
18 0,15711362
21 0,15259715
24 0,14890009
27 0,1461478
30 0,14216342
33 0,13898378
36 0,1354262
39 0,13205147
42 0,12884284
45 0,12620174
48 0,12381575
51 0,12065467
54 0,11798822
57 0,11514054
60 0,11260576
10
9
8
7
6
5
4
3
2
3
2
1
0
0
10
20
30
Axis Title
(A)
y = -0,0012x + 0,1804
R² = 0,9891
30
40
50
60
70
50
60
70
Axis Title
ln(A)
30
40
y = -0,0082x – 1,6977
R² = 0,9985
Axis Title
1/(A)
y = 0,0577x + 5,3391
R² = 0,9989
30
40
Axis Title
50
60
70
15 / 15
Overall Feedback
Objective:
2/2
Procedure: 2/2
Results/Expect: 5/5
Compare-others: 2/2
Apply/improve: 2/2
Grammar,etc: 2/2
Grade 15 out of 15 points
# Colligative Properties general comments (all students)
Objective: Several options here. An example, “The molecular
weight of ethylene glycol was determined by freezing point
depression.
Procedure: Should mention that data was collected on a Vernier
temperature probe.
Results: You should give the MW of ethylene glycol.
expectations: How far off are your numbers from theoretical
values? does that seem like more than there should be? You can
use freezing point of pure water here. If it is far from 0 then the
probe has some calibration error.
compare: how do your numbers compare to other students and
theoretical values? Be quantitative
Apply/ ve: must do both.
View Inline Feedback for post lab colligative properties.docx