Pearson Edexcel International GCSE in Chemistry · 4CH1
Topic 2 · Inorganic chemistry
The behaviour of real substances: Group 1 and Group 7 trends, the gases in air, the reactivity series and rusting, extracting metals, acids and alkalis, salt preparation and the chemical tests.
19 lessons, covering 50 specification statements: 2.1 · 2.2 · 2.3 · 2.4 · 2.5 · 2.6 · 2.7 · 2.8 · 2.9 · 2.10 · 2.14 · 2.11 · 2.12 · 2.13 · 2.15 · 2.16 · 2.17 · 2.18 · 2.19 · 2.20 · 2.21 · 2.22 · 2.23 · 2.24 · 2.25 · 2.26 · 2.27 · 2.28 · 2.29 · 2.30 · 2.31 · 2.32 · 2.33 · 2.40 · 2.34 · 2.35 · 2.36 · 2.37 · 2.38 · 2.39 · 2.42 · 2.41 · 2.43 · 2.44 · 2.49 · 2.50 · 2.45 · 2.46 · 2.47 · 2.48
The lessons
- Group 1 — the Alkali Metals — Metals soft enough to cut with a knife, which set fire to water — and get worse as you go down. (2.1, 2.2, 2.3, 2.4)
- Group 7 — the Halogens — A green gas, a brown liquid and a grey solid — and a trend that runs the opposite way to Group 1. (2.5, 2.6, 2.7, 2.8)
- The Gases in the Air — Four gases, one of which is doing almost all the chemistry — and how to measure it without ever touching it. (2.9, 2.10, 2.14)
- Combustion and Carbonates — Three things burning in oxygen, one carbonate breaking apart, and the 0.04% gas that changes the climate. (2.11, 2.12, 2.13)
- The Reactivity Series — Putting eleven metals in order by watching what each one will and will not do. (2.15, 2.16, 2.17)
- Rusting and its Prevention — Two things are needed to rust iron, and every method of stopping it removes one of them — or cheats. (2.18, 2.19)
- Redox — The same reaction described twice — once by what gains oxygen, and once by what loses electrons. (2.20, 2.21)
- Extracting Metals from their Ores — Where a metal sits in the reactivity series decides how much trouble it takes to get it out. (2.22, 2.23, 2.24)
- Uses of Metals, and Alloys — Why each metal is used where it is — and why almost none of them is used pure. (2.25, 2.26, 2.27)
- Acids, Alkalis and the pH Scale — Three indicators that answer a yes-or-no question, and one scale that answers 'how much'. (2.28, 2.29, 2.30)
- Hydrogen Ions and Neutralisation — What every acid has in common, what every alkali has in common, and why every neutralisation is one equation. (2.31, 2.32)
- Titrations — Finding the exact volume that neutralises — and then making the salt again without the indicator in it. (2.33, 2.40)
- Solubility Rules and Proton Transfer — Which salts dissolve, and the broader definition of an acid that explains why ammonia counts. (2.34, 2.35, 2.36)
- The Reactions of Acids — Three things acids react with, three sets of products, and one test that identifies a carbonate instantly. (2.37, 2.38)
- Preparing a Soluble Salt — Add too much on purpose, filter the excess away, and crystallise what is left. (2.39, 2.42)
- Preparing an Insoluble Salt — Mix two solutions, and the salt you want falls out of them as a solid. (2.41, 2.43)
- Tests for Gases, and for Water — Five gases, five tests — and the difference between something being water and being pure water. (2.44, 2.49, 2.50)
- Flame Tests — Five metal ions that announce themselves by the colour they give a flame. (2.45, 2.46)
- Tests for Ions — Sodium hydroxide identifies four cations by the colour of what falls out — and three anion tests complete the set. (2.47, 2.48)