Capstone: What does it make?
One skill ties the whole acids-and-metals half of C4 together: looking at the reactants and predicting the products. Each type of reaction has its own fixed pattern — acid + metal gives a salt + hydrogen, acid + base gives a salt + water, acid + carbonate adds carbon dioxide, and a displacement gives a salt + a displaced metal. Sort each reaction into the products it makes.
Drag each reaction into a box — or tap it to step through the boxes. Then press Check.
- Oxidation & reduction (oxygen): oxidation is gain of oxygen, reduction is loss of oxygen. Forming a metal oxide is oxidation.
- Reactivity series: metals ordered by their tendency to form positive ions, deduced from reactions with water and acid. Carbon and hydrogen are included as reference points.
- Displacement: a more reactive metal displaces a less reactive one from its compound. H It is redox — the more reactive metal is oxidised (loses electrons), the less reactive ion is reduced (gains electrons).
- Extracting metals: metals below carbon are extracted by reduction with carbon (heat the oxide with carbon); metals above carbon need electrolysis.
- Acids + metals: acid + metal → salt + hydrogen (only for metals above hydrogen). HCl → chlorides, H2SO4 → sulfates, HNO3 → nitrates.
- Neutralisation: acid + base → salt + water (carbonates also give CO2). Make a pure salt from an insoluble base by adding excess, filtering, then crystallising.
- pH scale: 0–14; acids release H+, alkalis release OH−. Neutralisation: H+ + OH− → H2O.
- Titration T: find reacting volumes with a burette, pipette and single-colour indicator. H Calculate concentrations using moles = concentration × volume and the mole ratio.
- Strong vs weak H: strong acids fully ionise, weak acids partially ionise. This is different from concentrated vs dilute. pH down 1 = H+ up ×10.
- Electrolysis: splits molten/dissolved ionic compounds. Cathode (−) attracts cations (reduced); anode (+) attracts anions (oxidised).
- Molten: metal at the cathode, non-metal at the anode. Aluminium is extracted from aluminium oxide dissolved in cryolite; carbon anodes burn away and are replaced.
- Aqueous: cathode gives hydrogen unless the metal is less reactive than hydrogen; anode gives the halogen if a halide is present, otherwise oxygen.
That completes C4. The reactions here build straight on the moles, masses and balanced equations of C3 — Quantitative Chemistry (which you need for the titration calculations), and they lead into C5 — Energy Changes, where you will look at the energy given out or taken in when these same reactions happen.