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[H + (aq)] [OH - (aq)] = 1 x 10 -14 mol 2 l -2 . So [OH - (aq)] = mol l -1 . = 1 x 10 -9 mol l -1. 1 x 10 -14 1 x 10 -5. HIGHER GRADE CHEMISTRY CALCULATIONS. pH is related to the concentration of hydrogen ions. e.g [H + (aq)] = 1 x 10 -1 mol l -1 , pH = 1
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[H+(aq)] [OH-(aq)]= 1 x 10-14 mol2 l-2. So [OH-(aq)]= mol l-1. = 1 x 10-9 mol l-1. 1 x 10-14 1 x 10-5 HIGHER GRADE CHEMISTRY CALCULATIONS pH is related to the concentration of hydrogen ions. e.g [H+(aq)] = 1 x 10-1 mol l -1, pH = 1 [H+(aq)] = 1 x 10-6 mol l -1, pH = 6 Also, in aqueous solution, [H+(aq)] x [OH-(aq)] = 1 x 10-14 mol2 l-2. pH and Concentration Worked example 1. What is the concentration of OH-(aq) in a solution with a pH of 5? pH = 5 [H+(aq)] = 1 x 10-5 mol l-1.
Calculations for you to try. 1. What is the pH of 0.01 mol l-1 hydrochloric acid? [H+(aq)] = 1 x 10-2 mol l-1. pH = 2 2. The concentration of [OH-(aq)] is 1 x 10-4 mol l-1. What is the pH of the solution? [OH-(aq)] = 1 x 10-4 mol l-1. H+(aq)] [OH-(aq)] = 1 x 10-14 mol2 l-2. So [H+(aq)] = 1 x 10-10 mol l-1. pH = 10 3. What is the pH of 0.05 mol l-1 sulphuric acid? [H+(aq)] = 2 x 0.05 = 0.1 mol l-1. Formula = (H+)2SO42- [H+(aq)] = 1 x 10-1 mol l-1. Higher Grade Chemistry pH = 1