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Theories of Acids and Bases

Chapter summary

Theories of Acids and Bases, at a glance

Follow protons, calculate strong-solution pH and explain how buffers respond to change.

A-Level 8873, revised syllabus (2026-2027)

Quick revision

Revisit the essentials, then return to an explanation when you need it.

Acid-base decisions
TaskMethod
Identify conjugate pairsSpecies differ by one H+ and one unit of signed charge.
Calculate strong-acid pHCount H+ per formula unit; find concentration; use -log10[H+].
Calculate strong-base pHCount OH-; use [H+] = Kw/[OH-]; then the logarithm.
Mix strong acid and alkaliNeutralise moles first; divide excess by total volume.
Choose an indicatorIts transition must lie in the steep supplied pH interval.
Explain bufferingName the component that consumes the added H+ or OH-.

Revisit an explanation

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