Chemistry study notes
Acid-Base Chemistry
Use ions and reaction patterns to explain acids, bases and salts.
O-Level 6092 (2026) / SEC G3 K324 (2027)
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7 topicsAcids, alkalis and pH
Read acidity as an ion balance, not just a colour.
Recognise the reaction pattern
Predict the salt and the other products.
Classify an oxide by its reactions
Metal/non-metal character suggests a pattern, but exceptions matter.
Strong and weak is different from concentrated and dilute
Separate extent of ionisation from amount per unit volume.
Pure onlyUse solubility rules to choose starting materials
An insoluble product can be separated as a precipitate.
Pure onlyPrepare and purify the salt you want
The method follows the solubility of both product and reactants.
Pure onlyAmmonia: choose useful industrial conditions
Reversible reactions require a balance between yield, speed and cost.
Pure only
Scope
Learning outcomes
5. Acid-Base Chemistry (6092 / K324). Use the outcome map to find the explanation for a particular syllabus requirement.
See the learning outcome map
5.1(a) Define acids and alkalis
- Aqueous H+ and OH-
- Universal Indicator
5.1(b) Compare acidity and alkalinity
- Relative ion concentrations
- Indicator colours
- pH scale, no logarithmic calculation
5.1(c) Distinguish strong and weak acids
- Extent of ionisation
- Distinguish concentration
5.1(d) Describe acid reaction patterns
- Metals, bases and carbonates
- Salt products
5.1(e) Explain neutralisation
- H+ + OH- -> water
5.1(f) Explain control of soil acidity
- Importance of soil pH
- Calcium hydroxide treatment
5.1(g) Describe base reactions
- With acids
- With ammonium salts on warming
5.1(h) Classify oxides
- Acidic, basic, amphoteric, neutral
- Metal/non-metal character and exceptions
5.2(a) Prepare, separate and purify salts
- Precipitation
- Titration
- Acids with metals, insoluble bases and insoluble carbonates
5.2(b) Apply salt-solubility rules
- Nitrates
- Chlorides including silver and lead
- Sulfates including barium, calcium and lead
- Carbonates and hydroxides
- Group 1 and ammonium salts
5.2(c) Select a salt-preparation route
- Suitable starting materials
- Product and reactant solubility
Use solubility rules to choose starting materialsPrepare and purify the salt you want
5.3(a) Identify ammonia feedstocks
- Nitrogen from air
- Hydrogen from cracking crude-oil hydrocarbons
5.3(b) Recognize reversibility
- Ammonia synthesis and decomposition
5.3(c) Interpret industrial process data
- Haber temperature, pressure, rate/yield/cost
- No Le Chatelier requirement