To determine the pH of various samples of sodium hydroxide, N-A-O-H, solution using pH paper, universal indicator solution, pH indicator is a chemical that turns different colors in different media. For example, blue litmus turns red in acidic medium and the red litmus turns blue in alkaline medium. MAM, how can we determine the pH of various samples of sodium hydroxide, any O-H solution? pH means potence hydrogen. This scale was discovered by Sorenson in 1909. This scale expresses the hydronium H3O positives ion concentration in a solution. The pH of a solution is defined as negative logarithm of hydronium ion or hydrogen ion concentration. pH is equal to minus log H3O positives or minus log H positives or H3O positives is equal to 1 into 10 raised to the power minus pH. If in a solution H3O positives is equal to OH negative is equal to if pH is equal to 7 solution is neutral. H3O positives greater than OH negative is equal to if pH less than 7 solution is acidic. H3O positives less than OH negative is equal to if pH greater than 7 solution is basic. Concept of strong and weak acids and bases. Strong acid is a strong electrolyte and its pH is less than 3. It completely ionizes to give large number of H positives ions example HCl, H2SO4, HN3 etc. Week acid is a weak electrolyte and its pH is more than 3 but less than 7. They weakly ionize in water. Example H3PO4H2CO3H2S CH3COOH. Strong base is a base whose pH is greater than 11. They completely ionize in water to give large number of OH negatives. Example NAHKOH. Week bases weak electrolyte whose pH is greater than 7 but less than 11. They weakly ionize in water to give lesser number of OH negatives. Example NH4OH. Carbonate. Bycarbonate. Posphate. Etc. Let's do an experiment to determine the pH of various samples of sodium hydroxide and a OH solution using pH paper. Universal indicator solution. Our aim here is to determine the pH of various samples of sodium hydroxide and a OH solution using pH paper. Universal indicator solution. Materials required are sodium hydroxide aqua solutions of different concentrations 0.1M 0.01M 0.001M pH paper. Universal indicator test tubes. Measuring cylinder. Test tube stand. Dropper. Etc. Procedure. Using universal indicator solution. Take three test tubes and two ML of NAHOID solution in each of them keep them in test tube stand. Now add 2 to 3 drops of universal indicator in each test tube and note the color and mark in the observation table. Using pH paper. Mark three pH papers as ABC and add 2 to 3 drops of each sample on the pH paper using dropper. Note the color change in mark the pH value in the observation table. Observation. Sample number. Concentration of NAHOH. Acquus. Universal indicator. Color. Approximate pH. pH paper. Color. Approximate pH. Calculated pH. pH is equal to 14-POH. pH plus POH is equal to 14. POH is equal to minus log OH negative. Result. pH of given NAHOH solution. 0.1M NAHOH is equal to x. 0.001M NAHOH is equal to x. 0.001M NAHOH is equal to x. Precautions. Equal number of universal indicator drops should be added in each test tube. The color of the solution should be matched very carefully with the pH chart. The pH paper should be kept at a safer place so that it may not get affected by the other laboratory reagents. Thank you, mom. We have understood the experiment very well.