Beatty 6092 Metals - Reactivity Series Rusting 2023

K Na Ca Mg Zn Fe Pb Cu Ag Reactivity Series of Metals More Reactive Less Reactive

Displacement of Metals from Aqueous Solutions Zn (s) + CuSO4 (aq) → ZnSO4 (aq) + Cu (s) Zn (s) + Cu2+ (aq) → Zn2+ (aq) + Cu (s) 2 oxidised to reduced to blue solution blue colour becomes fainter zinc rod

Displacement of Metals from Aqueous Solutions Observation & Explanation 3 Zinc is more reactive than copper. As such, zinc will dissolve and displace copper from its solution. The blue copper(II) sulfate solution turns to form a colourless solution. Reddish-brown/pink deposit of copper metal is also formed at the bottom of the solution.

Displacement of Metals from Aqueous Solutions • Copper metal with magnesium nitrate solution Observation & Explanation 4 Solution remains colourless. Magnesium is more reactive than copper. Hence, no displacement occurs.

Displacement of Metals from Metal Oxides • A metal higher in the reactivity series can reduce the oxide of a metal lower in the series. Aluminium powder is mixed thoroughly with iron(III) oxide and heated strongly. 2Al (s) + Fe2O3 (s) → 2Fe (l) + Al2O3 (s) This reaction is known as the thermit reaction, which releases a large amount of heat energy. This process is used to weld railway lines together, where the molten iron formed flows into the gaps between rails, joining them tightly together. 5

Displacement of Metals from Metal Oxides • A metal higher in the reactivity series can reduce the oxide of a metal lower in the series. Zinc reacts with copper(II) oxide (with magnesium ribbon acting as a fuse) Zn (s) + CuO (s) → ZnO (s) + Cu (s) 6 magnesium ribbon crucible sand mixture of zinc powder and copper(II) oxide

Quick Check! A large volume of copper(II) sulfate solution is left in an iron container overnight. Which statement describes what happens? A The solution evaporates completely and some copper(II) sulfate crystals are left behind. B The part of the container in contact with the solution is coated with copper. C Some fine iron particles are formed in the solution. D Atmospheric oxygen reacts with the copper(II) sulfate to give black copper(II) oxide. 7

K Na Ca Mg C Zn Fe Pb H Cu Ag Concept Map with by by as deduced from include have 8 Metals Physical Properties Chemical Properties Reactivity Series of Metals Reactions of Metals Water H2O(l) Steam H2O(g) Acid HCl(aq) Reduction of Metal Oxides Carbon C(s) Hydrogen H2(g) Decomposition of Metal Carbonates Heat Metal Displacement Reactions More Reactive Less Reactive

Learning Objectives • Describe the essential conditions for the corrosion (rusting) of iron as the presence of oxygen and water; prevention of rusting can be achieved by placing a barrier around the metal, e.g. painting; greasing; plastic coating; galvanising • Describe the sacrificial protection of iron by a more reactive metal in terms of the reactivity series where the more reactive metal corrodes preferentially, e.g. underwater pipes have a piece of magnesium attached to