know that a Brønsted–Lowry acid is a proton donor and a Brønsted–Lowry base is a proton acceptor
know that a Brønsted–Lowry acid is a proton donor and a Brønsted–Lowry base is a proton acceptor
know that acid-base reactions involve the transfer of protons
be able to identify Brønsted–Lowry conjugate acid-base pairs
be able to define the term ‘pH’
be able to calculate pH from hydrogen ion concentration
be able to calculate the concentration of hydrogen ions, in mol dm-3, in a solution from its pH, using the expression H+ = 10–pH
understand the difference between a strong acid and a weak acid in terms of degree of dissociation
be able to calculate the pH of a strong acid
be able to deduce the expression for the acid dissociation constant, Ka,for a weak acid and carry out relevant calculations
be able to calculate the pH of a weak acid making relevant assumptions
be able to define the ionic product of water, Kw
be able to calculate the pH of a strong base from its concentration, using Kw
be able to define the terms ‘pKa’ and ‘pKw’
be able to analyse data from the following experiments:
i) measuring the pH of a variety of substances, e.g. equimolar solutions of strong and weak acids, strong and weak bases, and salts ii) comparing the pH of a strong acid and a weak acid after dilution 10, 100 and 1000 times
be able to calculate Ka for a weak acid from experimental data given the pH of a solution containing a known mass of acid
be able to draw and interpret titration curves using all combinations of strong and weak monobasic acids and bases
be able to select a suitable indicator, using a titration curve and appropriate data
know what is meant by the term ‘buffer solution’
understand the action of a buffer solution
be able to calculate the pH of a buffer solution given appropriate data
be able to calculate the concentrations of solutions required to prepare a buffer solution of a given pH
understand how to use a weak acid–strong base titration curve to:
i) demonstrate buffer action ii) determine Ka from the pH at the point where half the acid is neutralised
understand why there is a difference in enthalpy changes of neutralisation values for strong and weak acids
understand the roles of carbonic acid molecules and hydrogencarbonate ions in controlling the pH of blood
CORE PRACTICAL 9: Finding the Ka value for a weak acid