In this video, universal indicator solution was applied for measuring the approximate pH of several consumer products:
1) Diluted hydrochloric acid; 0.1 M HCl, pH~1
2) Diluted acetic acid or vinegar; as a 3% solution of CH3COOH, pH~3
3) Lemon juice; containing citric acid-C3H4(OH)(COOH)3, pH~3
4) Orange juice; pH~3-4
5) Carbonated water; pH~5
6) Sodium chloride (table salt); solution of NaCl, pH~7
7) Sodium bicarbonate (baking soda); solution of NaHCO3, pH~9
8) Washing powder (as a solution); pH~10
9) A drain cleaner-”Torusiil" (Pipe Hedgehog); the main incredient is sodium hydroxide (NaOH) as a ~15% solution, pH>11
The results of the experiments do not provide exact figures, as the measurement accuracy of universal indicator does not allow it.
For the measurements of more accurate pH values, a pH-meter can be used. In this experiment, a pH-meter was used to measure the pH of Coca-Cola, providing a value of pH~2.7, which corresponds to a rather acidic drink. Coca-Cola contains several acids, like ortophosphoric acid (H3PO4) and citric acid.
1) SOLUTIONS, pH: “The color scale of the universal indicator”
2) SOLUTIONS, pH: “Strong and weak acids and bases”