Knowledge Organiser: Reactivity Series
Key Terms
- Reactivity: ease of losing outer electrons
- Oxidation: loss of electrons
- Reduction: gain of electrons
- Electrolysis: extraction above carbon
- Carbon reduction: extraction below carbon
- Native: found uncombined (Au, Ag, Pt)
Must-Know Facts
- Order: K > Na > Li > Ca > Mg > Al > C > Zn > Fe > H > Cu > Ag > Au
- K, Na, Li, Ca react vigorously with cold water → hydroxide + H₂
- Mg reacts slowly with cold water; vigorously with steam
- Zn, Fe react with steam only (not cold water)
- Metals above H react with dilute acid → salt + H₂
- Above C → electrolysis; below C → carbon reduction
- Reactivity: more shells + more shielding = weaker pull on outer electron = more reactive
Key Equations
- 2Na + 2H₂O → 2NaOH + H₂ (sodium + water)
- Mg + 2HCl → MgCl₂ + H₂ (metal + acid)
- 2Fe₂O₃ + 3C → 4Fe + 3CO₂ (carbon reduction of iron ore)
Common Mistakes
- Saying aluminium is less reactive than it appears: Aluminium has a protective oxide layer that prevents further reaction — it is actually very reactive
- Getting extraction method wrong: Metals above carbon in the reactivity series (e.g. aluminium, sodium) must be extracted by electrolysis — carbon cannot reduce them
- Confusing oxidation and reduction: OIL RIG — Oxidation Is Loss (of electrons); Reduction Is Gain (of electrons)
- Saying gold is found as a compound: Gold is below hydrogen in the reactivity series — it is found native (uncombined) in the Earth's crust
Memory Aid
- Above carbon → Electrolysis needed (E for Electrolysis, E for Extra reactive)
- Below carbon → Carbon reduction possible (C for Carbon, C for Cheaper)
- Found native (Au, Ag, Pt) → No extraction needed at all