IB DP Chemistry: Topic 8.3 The pH scale: Study Notes IB DP PhysicsIB DP MathsIB DP ChemistryIB DP Biology IBDP Chemistry: Study Notes- All Chapters IBDP Chemistry SL&HL: IB Style Question BankIBDP Physics SL&HL: IB Style Question BankIBDP Biology SL&HL: IB Style Question BankIBDP Maths AA&AI: IB Style Question Bank 8.3 The pH scale Essential idea: The pH scale is an artificial scale used to distinguish between acid, neutral and basic/alkaline solutions.Understandings:pH = −log[H+(aq)] and [H+] = 10−pH.A change of one pH unit represents a 10-fold change in the hydrogen ion concentration [𝐻+].pH values distinguish between acidic, neutral and alkaline solutions.The ionic product constant, 𝐾𝑤 = [H+][OH−] = 10−14 at 298 K.Applications and Skills:Solving problems involving pH,[H+] and [OH−].Students should be familiar with the use of a pH meter and universal indicator.