18. Acids and bases

18.5 – Indicators

18.5 – Indicators 18.5.1 - Describe qualitatively the action of an acid-base indicator Indicators change their colour depending on the pH of the solution. This is because they change forms depending on the H+ concentration, according to Le Chatelier’s principle. To...

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18.4 – Acid-Base Titrations

18.4 – Acid-Base Titrations 18.4.1 - Sketch the general shapes of graphs of pH against volume for titrations involving strong and weak acids and bases, and explain their important features When we perform a titration, we can sketch a titration curve to show how the pH...

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18.3 – Salt Hydrolysis

18.3 – Salt Hydrolysis 18.3.1 - Deduce whether salts form acidic, alkaline or neutral aqueous solution   Strong Acid and Strong Base The salt that is formed from a strong acid and a strong base will be neutral in solution. The Na+ and Cl- ions do not act as acids...

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18.2 – Buffer Solutions

18.2 – Buffer Solutions 18.2.1 - Describe the composition of a buffer solution and explain its action Buffer solutions maintain the pH of solutions by resisting changes caused by the addition of an acid or base.   Acidic Buffer Solution This is formed from a weak...

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18.1 – Calculations Involving Acids and Bases

18.1 – Calculations Involving Acids and Bases 18.1.1 - State the expression for the ionic product constant of water The ionisation of water happens according to the equation: Using this, we can find the expression of the equilibrium constant:   However, the...

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