Construct an expression, with Write an expression for Ka for What assumption do we make about the extent of dissociation when units, for the dissociation ethanoic acid dealing with weak acids? constant for a weak acid Ka Know that pKa = Ka an expression for pKa Is a smaller pKa a sign of a strong or weak acid? – Perform calculations relating Calculate the pKa of a solution of Calculate the concentration of Benzoic acid has a pKa of 4.20. the pH of a weak acid to the 0.1M ethanoic acid H+ in a solution of ethanoic acid Calculate its pH. dissociation constant, Ka, which has a pKa of 4.77 and the concentration Understand the typical shape Draw a pH curve for each of the following combinations: of pH curves for acid–base Strong acid and strong base b) Strong acid and weak base titrations Weak acid and strong base d) Weak acid and weak base Use pH curves to select an Describe how you would use a pH curve to choose an appropriate indictor for a titration appropriate indicator Perform calculations for the Calculate the concentration of Calculate the concentration of Prove that at the half-neutralisation titrations of monoprotic and the acid used when 25cm3 of the acid used when 25cm3 of point pKa = pH diprotic acids with sodium 0.2M NaOH is neutralise by 17cm3 0.5M NaOH is neutralise by hydroxide, based on of hydrochloric acid 17cm3 of sulfuric acid experimental results Explain qualitatively the Explain what a buffer solution is Describe the components Explain how the pH of a buffer solution is action of acidic and needed to make a buffer able to remain constant when buffers solution amounts of acid and base are added State applications of buffers Name everyday examples of buffers Be able to calculate the pH Calculate the pH of a buffer Calculate the pH of a buffer Calculate the new pH of the same of acidic buffer solutions which consists of 0.25M ethanoic formed when 25cm3 of 0. 5M buffer after 10cm3 of 0. 5M NaOH is acid and 0,25M sodium NaOH is added to 50cm3 of 2M added ethanoate (pKa ofEtOH= 4.77) ethanoic acid
Construct an expression, with units, for the dissociation constant Ka for a weak acid Write an expression for Ka for ethanoic acid What assumption do we make about the extent of dissociation when dealing with weak acids? Know that pKa = – Ka an expression for pKa Is a smaller pKa a sign of a strong or weak acid? Perform calculations relating the pH of a weak acid to the dissociation constant, Ka, and the concentration Calculate the pKa of a solution of 0.1M ethanoic acid Calculate the concentration of H+ in a solution of ethanoic acid which has a pKa of 4.77 Benzoic acid has a pKa of 4.20. Calculate its pH. Understand the typical shape of pH curves for acid–base titrations Draw a pH curve for each of the following combinations: Strong acid and strong base b) Strong acid and weak base Weak acid and strong base d) Weak acid and weak base Use pH curves to select an appropriate indicator Describe how you would use a pH curve to choose an appropriate indictor for a titration Perform calculations for the titrations of monoprotic and diprotic acids with sodium hydroxide, based on experimental results Calculate the concentration of the acid used when 25cm3 of 0.2M NaOH is neutralise by 17cm3 of hydrochloric acid Calculate the concentration of the acid used when 25cm3 of 0.5M NaOH is neutralise by 17cm3 of sulfuric acid Prove that at the half-neutralisation point pKa = pH Explain qualitatively the action of acidic and buffers Explain what a buffer solution is Describe the components needed to make a buffer solution Explain how the pH of a buffer solution is able to remain constant when amounts of acid and base are added State applications of buffers Name everyday examples of buffers Be able to calculate the pH of acidic buffer solutions Calculate the pH of a buffer which consists of 0.25M ethanoic acid and 0,25M sodium ethanoate (pKa ofEtOH= 4.77) Calculate the pH of a buffer formed when 25cm3 of 0. 5M NaOH is added to 50cm3 of 2M ethanoic acid Calculate the new pH of the same buffer after 10cm3 of 0. 5M NaOH is added
revision_helpsheets_acids.docx