A quick revision summary for right before the exam: every definition, reaction and the reactivity series, all in one place. The full notes are available separately for detailed reading.
1 Physical Properties
- Metals: lustrous, hard, malleable, ductile, good conductors of heat and electricity, sonorous
- Non-metals: the opposite of these, mostly solids/gases (bromine is liquid)
- Exceptions: mercury is liquid; iodine is lustrous; diamond/graphite (allotropes of carbon); alkali metals are soft
2 Definitions
A metal oxide that reacts with both acids and bases to give a salt and water. Examples: Al₂O₃, ZnO.
A list of metals in order of decreasing reactivity: K, Na, Ca, Mg, Al, Zn, Fe, Pb, [H], Cu, Hg, Ag, Au.
A compound formed by the transfer of electrons from a metal to a non-metal. E.g. NaCl, MgCl₂.
Mineral: a naturally occurring element/compound in the earth’s crust. Ore: a mineral from which extracting a metal is profitable.
Roasting: heating a sulphide ore in excess air. Calcination: heating a carbonate ore in limited air.
Fe₂O₃ + 2Al → 2Fe + Al₂O₃ + heat. Used to join railway tracks.
Alloy: a homogeneous mixture of two or more metals, or a metal and a non-metal. Amalgam: an alloy made with mercury.
3 Reaction of Metals with Water and Acids
| Metal | Cold water | Hot water | Steam |
|---|---|---|---|
| K, Na | Violent | × | × |
| Ca | Slower, floats | × | × |
| Mg | No | Yes, floats | × |
| Al, Fe, Zn | No | No | Yes |
| Pb, Cu, Ag, Au | Never | ||
Reactivity order with dilute acid: Mg > Al > Zn > Fe; copper does not react with dilute HCl.
Nitric acid exception: does not usually give H₂ (strong oxidising agent); only Mg and Mn give H₂ with very dilute HNO₃.
Aqua regia: concentrated HCl : concentrated HNO₃ = 3:1, can dissolve gold and platinum.
Non-metals: form acidic or neutral oxides (never basic); do not displace hydrogen from acids, react with hydrogen instead to form hydrides.
4 Key Equations
;
(2,8,1 → 2,8); (2,8,7 → 2,8,8)
;
(roasting)
(calcination)
+ heat (thermit)
5 Properties of Ionic Compounds
- Solid, somewhat hard but brittle
- Very high melting and boiling points (NaCl: 1074K/1686K)
- Soluble in water, insoluble in kerosene/petrol
- Do not conduct in the solid state; conduct in the molten/dissolved state
6 Extraction of Metals: Three Classes by Reactivity
| Class | Metals | Extraction method |
|---|---|---|
| Low reactivity | Around Cu, Ag, Au | Heating alone |
| Medium reactivity | Zn, Fe, Pb | Roasting/calcination → reduction with carbon |
| High reactivity | K, Na, Ca, Mg, Al | Electrolytic reduction |
Electrolytic refining: impure metal = anode, pure metal = cathode, metal salt solution = electrolyte. Insoluble impurities = anode mud.
7 Corrosion
- Rusting needs both air (oxygen) and water (Activity 3.14)
- Prevention: paint, oil/grease, galvanisation, chromium plating, anodising, alloying
- Galvanisation: stays protective even if scratched, because zinc is more reactive than iron
8 Alloys
| Alloy | Composition |
|---|---|
| Brass | Copper + zinc |
| Bronze | Copper + tin |
| Solder | Lead + tin |
| Stainless steel | Iron + nickel + chromium |
22-carat gold = 22 parts pure gold + 2 parts silver/copper (24-carat pure gold is too soft).
9 Key Points to Revise
- Write the full reactivity series (K to Au) from memory
- Amphoteric oxides, with the book’s examples Al₂O₃ and ZnO, and equations with both an acid and a base
- Roasting vs calcination: which acts on sulphides, which on carbonates
- NaCl is not a molecule, it is an aggregate of ions
- Rusting needs both air and water: neither alone is enough