pH calculations, indicator evidence and titration curves
≈ 50 minpH calculations, indicator evidence and titration curves
Acid-base representations connect numbers, graphs and experimental evidence. pH is logarithmic, so use powers of ten carefully. A titration curve plots pH against volume of titrant added and can show a rapid pH change near equivalence. The equivalence point is the stoichiometric point where reacting acid and base amounts match the balanced equation; an indicator end point is the observed colour change chosen to occur close to it. Select an indicator whose transition range lies in the steep region of the curve. A pH meter gives numerical data but needs calibration and clean technique.
Work it through
A strong acid at pH 3 has [H⁺] = 1.0 × 10⁻³ mol dm⁻³. At pH 2 it has ten times that concentration, 1.0 × 10⁻² mol dm⁻³. On a titration curve, do not infer exact pH values from an unlabelled sketch; read axes, scale and titrant volume. Use a balanced equation to connect curve features to mole evidence.
Mastery target
Move between hydrogen-ion concentration, pH, titration curve and balanced-equation stoichiometry while distinguishing equivalence evidence from indicator observation.
What is the equivalence point of a titration?
Name the key chemistry term from pH calculations, indicator evidence and titration curves that best fits the explanation and visual model.
What is [H⁺] in mol dm⁻³ for a solution with pH 3?
Which statement corrects a common misunderstanding in pH calculations, indicator evidence and titration curves?