Patterns of Reactivity

Properties of metals and non-metals Metals have very high melting points (which means that they are usually _____) whereas non-metals will melt at lower ___________ All metals conduct heat and __________ very well, whereas non-metals don’t (usually) Metals are strong and ______ but bendable. Non-metals are usually _____ or they will snap. Metals will _____ when freshly cut or scratched, whereas non-metals are usually dull Metals have higher _______ than non-metals (i.e. they weigh more) Metals can be used to make ______ (a mixture of different metals) Words - alloys, electricity, solids, weak, densities, temperatures, tough, shine

Reactions of metals with oxygen When a metal reacts with oxygen it will form a METAL OXIDE. This is what happens when a metal rusts or burns. METAL + OXYGEN METAL OXIDE Mg O Copy and complete the following reactions: Magnesium + oxygen Copper + oxygen Calcium + oxygen Iron + oxygen

Reactions of metals with water When a metal reacts with water hydrogen is always given off. The other product will be either a metal hydroxide or a metal oxide. METAL + WATER METAL OXIDE + HYDROGEN METAL + WATER METAL HYDROXIDE + HYDROGEN Copy and complete the following reactions: Sodium + water Potassium + water Calcium + water Iron + steam

Complete the following reactions: Lithium + water Lithium + hydrochloric acid Silver + oxygen Magnesium + sulphuric acid Potassium + oxygen Aluminium + oxygen Manganese + water Sodium + sulphuric acid Lithium + oxygen Nickel + hydrochloric acid Lithium hydroxide + hydrogen Lithium chloride + hydrogen Silver oxide Magnesium sulphate + hydrogen Potassium oxide Aluminium oxide Manganese oxide + hydrogen Sodium sulphate + hydrogen Lithium oxide Nickel chloride + hydrogen

Name the following compounds: For example: HS = Hydrogen sulphide Na2CO3 = sodium carbonate CO2 KBr HI NaCl CaCO3 MgCO3 MgSO4 KMnO4 Carbon dioxide Potassium bromide Hydrogen iodide Sodium chloride Calcium carbonate Magnesium carbonate Magnesium sulphate Potassium permanganate

Increasing reactivity The Reactivity Series Increasing reactivity Potassium Sodium Calcium Magnesium Aluminium Carbon Zinc Iron Lead Copper Silver Gold The Reactivity Series lists metals in order of reactivity:

Some example reactions… Prediction Observations Zinc + copper sulphate Zinc + lead nitrate Copper + lead nitrate Copper + silver nitrate Extension work – write down the equations for these reactions

Some example reactions… Prediction Observations Zinc + copper sulphate Reaction DID happen Zinc + lead nitrate Copper + lead nitrate Reaction DID NOT happen Copper + silver nitrate Extension work – write down the equations for these reactions

Reactions of metals with acids METAL + ACID SALT + HYDROGEN e.g. magnesium + hydrochloric acid magnesium chloride + hydrogen Mg H Cl Copy and complete the following reactions: Calcium + hydrochloric acid Zinc + hydrochloric acid Iron + hydrochloric acid Lithium + sulphuric acid

Reactions of metals carbonates with acid A metal carbonate is a compound containing a metal, carbon and oxygen. METAL CARBONATE + ACID SALT + CARBON DIOXIDE + WATER Mg H Cl C O Copy and complete the following reactions: Magnesium carbonate + hydrochloric acid Calcium carbonate + hydrochloric acid Sodium carbonate + sulphuric acid

Reactions of metal oxides with acid A metal oxide is a compound containing a metal and oxide. They are sometimes called BASES. For example: Mg O Na Al Magnesium oxide Sodium oxide Aluminium oxide METAL OXIDE + ACID SALT + WATER Mg O H Cl Copy and complete the following reactions: Magnesium oxide + hydrochloric acid Calcium oxide + hydrochloric acid Sodium oxide + sulphuric acid

Neutralisation reactions A neutralisation reaction occurs when an acid reacts with an alkali. An alkali is a metal oxide or metal hydroxide dissolved in water. ACID + ALKALI SALT + WATER Na Cl H O Copy and complete the following reactions: Sodium hydroxide + hydrochloric acid Calcium hydroxide + hydrochloric acid Sodium hydroxide + sulphuric acid Magnesium hydroxide + sulphuric acid

Burning Hydrogen Recall the test for hydrogen: The reaction: “POP” The reaction: O H Notice that no carbon dioxide or carbon monoxide is produced! H O Hydrogen Oxygen + Water

Displacement reactions A displacement reaction is one where a MORE REACTIVE metal will DISPLACE a LESS REACTIVE metal from a compound. Mg Magnesium SO4 Cu Copper sulphate The magnesium DISPLACES the copper from copper sulphate SO4 Mg Magnesium sulphate Cu Copper Magnesium + copper sulphate magnesium sulphate + copper

Energy from Displacement Reactions Increasing reactivity Potassium Sodium Calcium Magnesium Aluminium Carbon Zinc Iron Lead Copper Silver Gold In previous work we considered the reactivity series: We also looked at displacement reactions, where a more reactive metal will displace a less reactive one from one of its compounds.

Energy from Displacement Reactions Lots of energy Example 1 – Magnesium and copper sulphate O Cu S Copper sulphate + Mg O S Magnesium sulphate + Cu Copper Mg Magnesium Some energy Example 2 – Zinc and copper sulphate Zn O Cu S Zinc + Copper sulphate Copper Zinc sulphate

Electrical energy from differences in reactivity Zinc rod Copper rod Filter paper soaked in potassium nitrate V Zinc sulphate Copper sulphate The bigger the difference in reactivity, the bigger the voltage

Conservation of mass in reactions In any reaction the total mass of products is the same as the total mass of the reactants Example 1 – Magnesium oxide and hydrochloric acid Mg O H Cl 1 x magnesium, 1 x oxygen, 2 x hydrogen and 2 x chlorine atoms Also 1 x magnesium, 1 x oxygen, 2 x hydrogen and 2 x chlorine atoms Example 2 – Burning methane C H O