pH of Common Substances and Compounds

Denise Arandia Michelle Armario Raisa Crisologo Joshua Fernandez Ryan Santos

Introduction What is pH? A measurement used in order to indicate whether a substance/mixture is acidic or basic. The negative logarithm of the hydrogen ion concentration.

Procedure PART 1: Number the test tubes from 1-13. Add 5 mL of each solution to each test tube. Test Tube 1: Most concentrated acid Test Tube 7: 0.01M NaCl solution Test Tube 8: Least concentrated base. Add a few drops of indicator solution and observe the results.

Procedure PART 2: Determine the pH range of the various substances and mixtures suggested by the instructor. Feminine Wash Tears Body Wash Sugar Sprite Alcohol

Results [H3O+] (M) [OH-] (M) pH Color 1 x 10-1 1 x 10-13 1 Dark red 2 Red 1 x 10-3 1 x 10-11 3 Red orange 1 x 10-4 1 x 10-10 4 Orange 1 x 10-5 1 x 10-9 5 Yellow orange 1 x 10-6 1 x 10-8 6 Lighter yellow orange 1 x 10-7 7 Dark yellow 8 Yellow 9 Yellow green 10 Darker yellow green 11 Green 12 Blue 13 Dark blue/ purple

Results Substance/Mixture Observations pH Range Feminine Wash Bubbly, yellow orange 5 Tears Dark green 11-12 Body Wash Sugar Yellow orange 7-8 Sprite Bubbly, light red 2-3 Acetone Red 1-2

Conclusion Indicator Dye that changes color Acid-base Weak organic acids (different colors from their conjugate bases) Range of hydrogen ions Phenolphtalein pH measured with pH meter (numerical value)

Applications

Aquariums Some fish can only live in a certain range of pH leve of water. An ideal pH for goldfish to live safely is 6.6-8.4

Commercial Products Liquid soap usually has a pH level of 6-10. Having a high pH level makes the soap more anti-bacterial. Shampoo has a slightly acidic pH level since a more basic environment weakens the hair.

Plants The ideal pH living conditions for common fruits and vegetables is around 4.5-7.5. Using limestone could increase the pH level of soil while using aluminum sulfate can lower pH levels.

Marine Life Corals are very sensitive to the pH of the seawater. They only survive in 8.3-8.5 pH. If the pH of the seawater drops or increases, the corals would eventually die.