the study aims to determine whether crushed crab shells can be a potential ph buffer. crushed crab...
TRANSCRIPT
The Potential of Crushed Crab Shells as a pH Buffer
Marx Caesar S. BarluadoMishari Rashid M. Lucman
What is the study all about?
The study aims to determine whether crushed crab shells can be a potential pH buffer. Crushed crab shells contain calcium carbonate which is believed to be a potential pH buffer. Which then leads to production of cheaper buffers compared to commercial ones.
Statement of the Problem
The evaluation of crushed crab shells as a potential pH
buffer.
Sub-Problems
1. What is the characteristic of the experimental pH buffer in terms of:a)Buffer pH; andb)Buffer capacity?
2. What is the effectiveness of the experimental pH buffer when compared to water upon the addition of:a) Weak acidb) Weak base?
3. In what type of substance (weak acid or weak base) is the experimental buffer most effective?
4. Is there a significant difference between the trend of the pH changes of experimental buffer and water upon the addition of:a) Weak acidb) Weak base?
Scope and Limitations This study focuses on determining the potential
of crushed crab shells as pH buffer to weak acid and basic solutions. This study will focus only on crab shells and not on other potential components. We will include the comparison of the experimental buffer and the water’s change in pH upon every addition of weak acid or weak base. We will keep the volume of the solvent and the amount of the solute constant at 100 milliliters and 0.5 grams respectively. We will not include tests on elements, compounds, and living organisms.
Procedures
Use of statistical tool to summarize data
Data gathering
Determination of pH level
Calibration of pH meter
Preparation of experimental buffer solution
Preparation of Materials
Procedures
Procedures
Resulting pH levels upon the addition of base
Base Water (pH) Solution (pH)
O drops 7.3 9.86
1 drop 8.41 9.88
2 drops 8.6 9.88
3 drops 8.88 9.9
4 drops 9.14 9.91
5 drops 9.31 9.91
6 drops 9.56 9.92
7 drops 9.61 9.93
8 drops 9.68 9.93
9 drops 9.73 9.93
10 drops 9.77 9.94
11 drops 9.81 9.95
12 drops 9.84 9.96
13 drops 9.87 9.96
14 drops 9.89 9.97
15 drops 9.91 9.98
2 mL 10.07 10.04
3 mL 10.15 10.06
4 mL 10.24 10.09
5 mL 10.31 10.11
6 mL 10.34 10.14
7 mL 10.37 10.15
8 mL 10.39 10.16
9 mL 10.4 10.18
10 mL 10.4 10.19
11 mL 10.41 10.2
12 mL 10.42 10.2
13 mL 10.43 10.21
14 mL 10.43 10.22
15 mL 10.44 10.24
16 mL 10.45 10.25
17 mL 10.46 10.26
18 mL 10.48 10.27
19 mL 10.49 10.27
20 mL 10.5 10.28
21 mL 10.51 10.29
Resulting pH levels upon the addition of acid
Acid Water (pH) Solution (pH)
0 drops 7.32 9.87
1 drop 7.17 9.86
2 drops 7.07 9.85
3 drops 6.99 9.83
4 drops 6.86 9.82
5 drops 6.78 9.81
6 drops 6.7 9.79
7 drops 6.65 9.78
8 drops 6.59 9.78
9 drops 6.54 9.77
10 drops 6.48 9.76
11 drops 6.44 9.75
12 drops 6.39 9.73
13 drops 6.36 9.73
14 drops 6.33 9.73
15 drops 6.3 9.72
2 mL 6.1 9.64
3 mL 5.98 9.62
4 mL 5.89 9.59
5 mL 5.81 9.56
6 mL 5.75 9.54
7 mL 5.68 9.53
8 mL 5.6 9.51
9 mL 5.54 9.49
10 mL 5.5 9.48
11 mL 5.47 9.47
12 mL 5.43 9.45
13 mL 5.39 9.45
14 mL 5.36 9.44
15 mL 5.32 9.43
16 mL 5.29 9.41
17 mL 5.27 9.4
18 mL 5.26 9.39
19 mL 5.24 9.38
20 mL 5.23 9.38
21 mL 5.22 9.37
Analysis of Data Z-test Paired Observation at 0.05 level
of significance was used as the statistical tool.
For the Addition of Base
Hypothesis Test: Paired Observations
0.00000 hypothesized value0.06000 mean w0.01429 mean a0.04571 mean difference (w - a)0.03441 std. dev.0.00582 std. error35 n
7.86 z3.77E-15 p-value (two-tailed)
Hypothesis Test: Paired Observations
0.00000 hypothesized value0.09171 mean w0.01229 mean b0.07943 mean difference (w - b)0.19199 std. dev.0.03245 std. error35 n
2.45 z.0144 p-value (two-tailed)
For the Addition of Acid
Graph for the addition of Weak Acid
1 3 5 7 9 11 13 15 45 75 105
135
165
195
225
255
285
315
0
0.5
1
1.5
2
2.5
Changes in pH level: Water Vs. Experimental Buffer
water
experimental buffer
No. of drops
Diff
ere
nce
of
final pH
and init
ial pH
Graph for the addition of Weak Base
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 30 45 60 75 90 105
120
135
150
165
180
195
210
225
240
255
270
285
300
315
0
0.5
1
1.5
2
2.5
3
3.5
Changes in pH Level: Water Vs. Experimental Buffer
solution
water
No. of drops
Diff
ere
nce
of
final pH
and init
ial pH
Significance of the study
If proven to be a pH buffer we can create more cheaper and local pH buffers.
It can be applied to areas which are affected by acid rains
Instead of dumping the crab’s leftovers we can use them as buffers.
Conclusions1. The crushed crab shells are potential pH
buffer since changes in pH level of the experimental buffer were minimal in both the addition of weak acid and base.
2. The crushed crab shells are more effective as pH buffer during addition of weak base since the final change in pH upon addition of weak base was more minimal than in the addition of weak acid.
3. The change in pH level of the experimental buffer in every addition of weak acid or weak base is not the same with water’s change in pH level.
Recommendations
1. To use other substance that could be a source of calcium carbonate and could be a potential pH buffer.
2. To include strong base and strong acid in determining the change in pH level.
3. Find ways to fully dissolve the crab shells in water.
4. To develop the solution’s appearance close to the commercially available pH buffer.
5. To develop the potential of crab shells into a commercial buffer.
Bibliography
•Groiler: Encyclopedia of Knowledge (No. 5C-D) © MCMXCL Groiler Incorporated•Vivian Corry & Christopher Cooper. (1980). New Encyclopedia of Science (No. 4, Ca-Er) © Orbis Publishing Limited •Neil A. Campbell, Lawrence G. Mithcell & Jane B. Reece. (2000). Biology – Concepts and Connections: International Edition © Pearson Education Asia Pte Ltd• Estrella E. Mendoza & Teresita F. Religioso. (1997). Science and Technology – Chemistry; Second Edition © Phoenix Publishing House Inc.
Bibliography•pH color charts. (2010, February 20). Retrieved September 23, 2011, Website:
http://www.ncsu.edu/sciencejunction/depot/experiments/water/lessons/pH/ •Crab’s Gender and Age. (2010, January 11).
Retrieved September 23, 2011, Website: http://skipjack.net/le_shore/crab/crab_ages.htm•Crab recipes. (2010, June 18). Retrieved September 23, 2011, Website: http://www.aquaticfilipinorecipes.filipinovegetarianrecipe.com/crab_recipes.htm
Bibliography
•Arocha, Izel Faith Abrasaldo. (2009). Utilization of Seashells for Chalk Formulation (2009-No. 771)
•Jutba, Danessa Ausejo. (2007). Effect of Recylced Crab Shells Unto Hardness of Exoskeleton of Pre-Molt Mud Crabs (2007-No. 511)