Data:
Standardization of HCl Solution with Microlab Software:
Microlab Standardization of HCl Titration Curve
14
12
pH
10
8
6
4
2
0
0
5
10
15
20
25
mL HCl added
30
35
40
Figure 1: Example of HCl Titration Curve Being Standardized With Known Amounts of
Na2CO3 Using Microlab Software for Analysis. Note the end point that is shaded.
Original volumes were measured in drops, and then converted to mL after calibration,
which may be assumed for all trials using Microlab software in this experiment.
Trial 1
Trial 2
Trial 3
g Na2CO3
0.1306
0.1328
0.1325
mL H2O
25
25
25
CO32-
mol
0.00123
0.00125
0.00125
mol H+ needed to
reach end point
0.00246
0.0025
0.0025
HCl added to reach
end point / mL
24.505
26.593
25.44
Average M HCl
0.098
St Dev
0.003
M HCl
0.10038767
0.09400970
0.09827044
Table 1: Standardization of HCl Solution Using Titration Techniques with Microlab
Software for Analysis and Known Amounts of Na2CO3. The average concentration of
our acid using Microlab software was found to be 0.098 ± 0.003 M, where the uncertainty
represents standard deviation.
Standardization of HCl Solution Using a Buret:
g Na₂CO₃
0.1374
0.1307
0.1294
0.1370
Trial 1
Trial 2
Trial 3
Trial 4
mL H₂O
24.8
24.7
25.1
25.0
mol CO₃²⁻
0.00129634
0.00123313
0.00122087
0.00129257
mol H⁺ needed to
reach end point
0.00259269
0.00246627
0.00244174
0.00258515
Average M HCl
0.092
HCL added to reach
end point / mL
26.90
26.87
28.10
27.57
M HCl
0.096382804
0.091785277
0.086894654
0.093766759
St Dev
0.004
Table 2: Standardization of HCl Solution Using Titration Techniques with a Buret and
Known Amounts of Na2CO3. The average concentration of our acid using a buret was
found to be 0.092 ± 0.004 M, where the uncertainty represents standard deviation.
Because of the higher deviation calculated using the buret technique, the concentration
calculated using Microlab software (Table 1) was used to identify our acid.
Standardization of NaOH Solution Using Microlab Software:
Microlab Standardization of NaOH Titration Curve
14
12
pH
10
8
6
4
2
0
0
5
10
15
mL NaOH added
20
25
Figure 2: Example of NaOH Titration Curve Being Standardized With Known Amounts
our Previously Standardized HCl Using Microlab Software for Analysis. Note the end
point that is shaded.
Trial 1
Trial 2
Trial 3
Trial 4
M HCl
0.098
0.098
0.098
0.098
mL HCl
24.8
23.0
23.9
24.1
mol H⁺
0.00243
0.00225
0.00234
0.00236
mol OH⁻ needed to
reach end point
0.00243
0.00225
0.00234
0.00236
NaOH added to
reach end point / mL
24.38
19.73
19.86
19.55
Average M HCl
0.113
St Dev
0.009
M NaOH
0.099671862
0.114039533
0.117824773
0.120716112
Table 3: Standardization of NaOH Solution Using Titration Techniques with Microlab
Software for Analysis and Known Amounts of our Previously Standardized HCl. The
average concentration of our base using Microlab software was found to be 0.113 ± 0.009
M, where the uncertainty represents standard deviation.
Standardization of NaOH Solution Using a Buret:
Trial 1
Trial 2
Trial 3
M HCl
0.098
0.098
0.098
mL HCl
20.0
22.0
20.0
mol H⁺
0.00196
0.00216
0.00196
mol OH⁻ needed
to reach end point
0.00196
0.00216
0.00196
NaOH added to
reach end point / mL
20.20
22.60
20.72
Average M NaOH
0.096
St Dev
0.001
M NaOH
0.09702970
0.09539823
0.09459459
Table 4: Standardization of NaOH Solution Using Titration Techniques with a Buret
and Known Amounts of our Previously Standardized HCl. The average concentration of
our acid using a buret was found to be 0.096 ± 0.001 M, where the uncertainty represents
standard deviation. Because of the higher deviation calculated using the Microlab
software, the concentration calculated using the buret was used to identify our base.
Titrations to Determine Amount of Citric Acid in Powerade Using Microlab Software:
Titration Curve for Citric Acid in Powerade
12
10
pH
8
6
4
2
0
0
2
4
6
8
10
mL NaOH added
12
14
16
18
Figure 3: Example of Citric Acid in Powerade Titration Curve With Known Amounts of
our Previously Standardized NaOH Using Microlab Software for Analysis. The
concentration of NaOH was obtained from Table 4. Note the end point that is shaded.
Trial 1
Trial 2
Trial 3
Trial 4
mL Powerade
NaOH added needed to
reach end point / mL
mol NaOH added to
reach end point
mol citric acid reacted
to reach end point
M citric acid
in Powerade
31.0
30.7
30.7
30.5
10.9659
10.8523
11.7046
10.1136
0.001052726
0.001041821
0.001123637
0.000970909
0.001052726
0.001041821
0.001123637
0.000970909
0.033958916
0.033935531
0.036600547
0.031833096
Average M Citric Acid
St Dev
0.034
0.002
Table 5: Titrations of Powerade for Determining Concentration of Citric Acid Using
Microlab Software and Known Amounts of our Previously Standardized NaOH. The
concentration of NaOH was obtained from Table 4. The average concentration of citric
acid in Powerade was using Microlab Software for analysis was found to be 0.034 ±
0.002 M. The Powerade was not diluted.
Titrations to Determine Amount of Citric Acid in Powerade Using a Buret:
Trial 1
Trial 2
Trial 3
Trial 4
mL Powerade
31.2
30.6
30.9
31.0
NaOH added needed to
reach end point / mL
11.84
10.70
10.66
11.10
mol NaOH added to
reach end point
0.0011366
0.0010272
0.0010233
0.0010656
mol citric acid reacted
to reach end point
0.0011366
0.0010272
0.0010233
0.0010656
Average M Citric Acid
0.0344
St Dev
0.0015
M citric acid
in Powerade
0.036430769
0.033568627
0.033118447
0.034374194
Table 6: Titrations of Powerade for Determining Concentration of Citric Acid Using a
Buret and Known Amounts of our Previously Standardized NaOH. The concentration of
NaOH was obtained from Table 4. The average concentration of citric acid in Powerade
when using Microlab Software for analysis was found to be 0.0344 ± 0.0015 M. The
Powerade was not diluted. Results using Microlab software and a buret for determining
amount of citric acid in Powerade were very consistent.
Conclusion: Using data obtained with Microlab, the concentration of our standardized
acid was .098 ± .003 M, while using data obtained with a buret, the concentration of our
standardized base was .092 ± .002 M. After using the standardized base to neutralize the
citric acid in undiluted blue powerade, we found that the average concentration of citric
acid was 0.034 ± 0.002 M.
Discussion: Unfortunately, we were not able to locate a more exact concentration of citric
acid in powerade, as it is only described as less than 5% of the ingredients, so no
comparison could be made between the actual concentration and the concentration we
discovered in lab.
In comparing the two methods of titration, we were able to receive reliable results from
both Microlab and a buret. The standard deviation of the concentration of our acid was
lower with microlab, indicating a more precise value; however, the difference between
the standard deviations of Microlab and the buret was .001 M. We see a bit different
results when standardizing our base, as the buret was actually the more precise
instrument, with a standard deviation of .001 M as compared to the standard deviation of
Microlab, which was .009 M. Our hypothesis had been that being able to count specific
drops and monitor the pH with Microlab would have given it an edge over the less
technical buret, when indeed the opposite was true. An issue with Microlab was that our
titrant would splash onto the drop counter, despite our efforts to fix this problem. In
addition, the buret was able to deliver less than a drop of titration which could have
produced a more precise end point.