Work through the list without notes. If you cannot do a statement, follow its link, then come back. Guide = study guide; Practice = practice questions.
Understanding
- I can define buffer capacity and explain how it differs from buffer pH. (Guide: “What buffer capacity means”; Practice Q1)
- I can write the reaction that uses up added strong acid, and the one that uses up added strong base, in a buffer. (Guide: “What buffer capacity means”; Practice Q5(b))
- I can explain why raising both concentrations at a fixed ratio keeps the pH the same but increases the capacity. (Guide: “Same ratio, more concentrated”; Practice Q1, Q7(a))
- I can explain why diluting a buffer keeps its pH but lowers its capacity per litre (or per sample). (Practice Q6(d))
Calculation
- I can calculate the maximum moles of strong acid or strong base a buffer can neutralise. (Practice Q3, Q5(b))
- I can decide whether a buffer will cope with a given addition or be overwhelmed. (Guide: Worked examples 1 and 2; Practice Q2, Q5(c))
- I can find the concentrations needed for a buffer with a given pH and a minimum capacity. (Practice Q7(b))
Reasoning
- I can predict whether a buffer with unequal amounts resists added acid or added base better. (Guide: “Unequal amounts”; Practice Q4, Q7(c))
- I can convert volumes and concentrations to moles before judging capacity, including for buffers of different volumes. (Guide: “How to compare capacities”; Practice Q3)
- I can explain how an error in a titrant concentration, a dilution or a pH-meter offset affects measured pH and measured capacity. (Guide: Worked example 3; Practice Q6)
- I can evaluate a claim that two buffers with the same pH are equally effective. (Practice Q7(a))
All ticked? Move on to Topic 8.11, pH and Solubility, or return to the course roadmap.