Helping students to make links to previous key ideas of acids and bases topics.

Buffers builds on students' understanding of strong and weak meanings, ie appreciate that a weak acid will partially dissociate into ions, while HA remains. This equilibrium can change subject to other additions. Similarly, if some strong acid is added to the buffer, understanding that it fully dissociates to H+ and A-.

Understanding of conjugate acids and base pairs. Recognising these pairs.

Understanding of [H+] concentration.

Buffer capacity - cover this or not? If so, simple sketches or lego models similar to the 'explaining acid strength' activity could be done.