Unit 9
Acids and bases.
Ions in water: strong and weak acids and bases, pH as a logarithm, neutralisation, and titration drop by drop.
Before this unit
- Solutions
- Equilibrium
- Exponents and logarithms Mathematics
The unit, lesson by lesson
Lessons
4 lessons · 21 practice questions · about 2 hours
Acids, bases and ions in water
What makes a solution acidic or basic: hydronium and hydroxide ions, water that splits by itself, and the difference between a strong acid and a concentrated one.
The pH scale
pH as a logarithm: minus the exponent of the hydronium concentration, one step that is ten times, working out pH from a concentration and back, dilution, and bases on the same scale.
Neutralisation and titration
An acid and a base that give a salt and water, a pH curve that leaps near the equivalence point, and titrating drop by drop to measure an unknown concentration.
Titration curves and indicators
A weak acid on the curve: a pH that climbs gradually, an equivalence point above 7 and the pKa half way. And how to choose an indicator that changes colour right on the steep part.