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Yasmin Gesey
Pharmaceutical Science
000763144
Experiment 5
Figure 1:
0.01 mol dm-3 hydrochloric acid (HCL) with 0.01 mol dm-3 Sodium Hydroxide (NaOH)
Vol. of base added (cmP3P) | pH | pH/V | colour |
0.00 | 1.97 | Colourless | |
5.01 | 2.07 | Colourless | |
10.05 | 2.21 | Colourless | |
15.00 | 2.41 | Colourless | |
20.01 | 2.74 | Colourless | |
21.00 | 2.89 | Colourless | |
22.00 | 3.03 | Colourless | |
22.9 | 3.25 | Colourless | |
24.00 | 3.49 | Colourless | |
25.2 | 5.22 | Colourless | |
26.1 | 6.42 | Colourless | |
27.01 | 8.24 | Light pink | |
27.2(Endpoint) | 8.86 | Light pink |
Figure 2:
0.01 mol dm-3 Hydrochloric Acid (HCL) with 0.01 mol dm-3 Ammonia (NH3)
Vol. of base added (cmP3P) | pH | pH/V | colour |
0.00 | 1.97 | Pink | |
5.15 | 2.00 | Pink | |
10.00 | 2.14 | Pink | |
15.10 | 2.31 | Pink | |
20.10 | 2.52 | Pink | |
21.10 | 2.58 | Pink | |
22.00 | 2.64 | Pink | |
23.00 | 2.70 | Pink | |
24.00 | 2.76 | Pink | |
25.00 | 2.84 | Light pink | |
26.00 | 2.94 | Light pink | |
27.00 | 3.06 | Light pink | |
27.20 | 3.10 | Light pink | |
28.00 | 3.22 | Light pink | |
29.00(Endpoint) | 3.40 | Light orange |
Figure 3:
0.01 mol dm-3 ethanoic acid (C2H4O2) with 0.01 mol dm-3 Sodium Hydroxide (NaOH)
Vol. of base added (cmP3P) | pH | pH/V | colour |
0.00 | 3.32 | ||
5.0o | 4.06 | ||
10.00 | 4.49 | Colourless | |
15.25 | 4.88 | Colourless | |
20.00 | 5.33 | Colourless | |
21.00 | 5.48 | Colourless | |
22.00 | 5.65 | Colourless | |
23.10 | 5.90 | Colourless | |
24.00 | 6.17 | Colourless | |
24.20 | 6.30 | Colourless | |
24.60 | 6.37 | Colourless | |
25.00 | 6.61 | Colourless | |
25.50 | 6.86 | Colourless | |
26.00 | 7.39 | Colourless | |
26.25 | 8.18 | Slightly pink | |
26.50 (Endpoint) | 8.96 | Pink |
Figure 4:
0.01 mol dm-3 Ethanoic Acid (C2H4O2) with 0.01 mol dm-3 ammonia (NH3)
Vol. of base added (cmP3P) | pH | pH/V | colour |
0.00 | 3.35 | Colourless | |
5.10 | 4.03 | Colourless | |
9.90 | 4.33 | Colourless | |
15.00 | 4.65 | Colourless | |
20.00 | 4.96 | Colourless | |
21.00 | 4.99 | Colourless | |
22.10 | 5.09 | Colourless | |
23.00 | 5.35 | Colourless | |
24.00 | 5.26 | Colourless | |
25.00 | 5.69 | Colourless | |
26.00 | 4.47 | Colourless | |
27.20 | 5.61 | Colourless | |
28.00 | 5.75 | Colourless | |
29.50 | 6.06 | Colourless | |
30.00 | 6.17 | Colourless | |
31.00 | 6.40 | Colourless | |
32.00 | 6.82 | Colourless | |
33.20 | 7.75 | Colourless | |
35.00 | 8.21 | Colourless | |
36.00 | 8.08 | Colourless | |
37.00 | 8.34 | Colourless | |
38.10 | 8.48 | Colourless | |
39.00 | 8.67 | Colourless | |
40.20 | 8.56 | Colourless | |
41.00 | 8.64 | Colourless | |
42.00 | 8.66 | Colourless | |
43.05 | 8.80 | Colourless | |
44.20 | 8.83 | Colourless | |
45.30 | 8.84 | Colourless | |
46.15 | 8.87 | Colourless | |
47.00 | 8.86 | Colourless | |
48.00 | 8.91 | Colourless | |
49.10 | 8.94 | Colourless | |
50.10 | 8.97 | Colourless | |
51.00 | 9.00 | Colourless |
In your conclusions comment on the ease of determining the end-point and discuss any differences between the values obtained.
Please draw all graphs on graph paper or use a computer program such as Excel or OfficeHD. Please add your graphs in the box below and the following page.
QUESTIONS
Why does an acid-base titration curve (pH versus volume of titrant) have an abrupt change at the equivalence point for the strong acid - strong base titration system?
Why does a properly chosen indicator change colour near the equivalence point in a titration?