2.  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.

3. TThe evaluation of crushed crab shells as a potential pH buffer.

4. 1. What is the characteristic of the experimental pH buffer in terms of: a) Buffer pH; and b) Buffer capacity? 2. What is the effectiveness of the experimental pH buffer when compared to water upon the addition of: a) Weak acid b) Weak base?

5. 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 acid b) Weak base?

6.  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.

7. 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

10. BaseWater (pH)Solution (pH) O drops7.39.86 1 drop8.419.88 2 drops8.69.88 3 drops8.889.9 4 drops9.149.91 5 drops9.319.91 6 drops9.569.92 7 drops9.619.93 8 drops9.689.93 9 drops9.739.93 10 drops9.779.94 11 drops9.819.95 12 drops9.849.96 13 drops9.879.96 14 drops9.899.97 15 drops9.919.98 2 mL10.0710.04 3 mL10.1510.06 4 mL10.2410.09 5 mL10.3110.11 6 mL10.3410.14 7 mL10.3710.15 8 mL10.3910.16 9 mL10.410.18 10 mL10.410.19 11 mL10.4110.2 12 mL10.4210.2 13 mL10.4310.21 14 mL10.4310.22 15 mL10.4410.24 16 mL10.4510.25 17 mL10.4610.26 18 mL10.4810.27 19 mL10.4910.27 20 mL10.510.28 21 mL10.5110.29

11. AcidWater (pH)Solution (pH) 0 drops7.329.87 1 drop7.179.86 2 drops7.079.85 3 drops6.999.83 4 drops6.869.82 5 drops6.789.81 6 drops6.79.79 7 drops6.659.78 8 drops6.599.78 9 drops6.549.77 10 drops6.489.76 11 drops6.449.75 12 drops6.399.73 13 drops6.369.73 14 drops6.339.73 15 drops6.39.72 2 mL6.19.64 3 mL5.989.62 4 mL5.899.59 5 mL5.819.56 6 mL5.759.54 7 mL5.689.53 8 mL5.69.51 9 mL5.549.49 10 mL5.59.48 11 mL5.479.47 12 mL5.439.45 13 mL5.399.45 14 mL5.369.44 15 mL5.329.43 16 mL5.299.41 17 mL5.279.4 18 mL5.269.39 19 mL5.249.38 20 mL5.239.38 21 mL5.229.37

12.  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 0.00000hypothesized value 0.06000mean w 0.01429mean a 0.04571mean difference (w - a) 0.03441std. dev. 0.00582std. error 35n 7.86 z 3.77E-15 p-value (two-tailed) Hypothesis Test: Paired Observations 0.00000hypothesized value 0.09171mean w 0.01229mean b 0.07943mean difference (w - b) 0.19199std. dev. 0.03245std. error 35n 2.45 z.0144 p-value (two-tailed) For the Addition of Acid

15.  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.

16. 1. 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.

17. 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.