2 Inorganic chemistry

Understand how the similarities in the reactions of these elements with water provide evidence for their recognition as a family of elements

Understand how the differences between the reactions of these elements with air and water provide evidence for the trend in reactivity in Group 1

Use knowledge of trends in Group 1 to predict the properties of other alkali metals

Explain the trend in reactivity in Group 1 in terms of electronic configurations

Know the colours, physical states (at room temperature) and trends in physical properties of these elements

Use knowledge of trends in Group 7 to predict the properties of other halogens

Understand how displacement reactions involving halogens and halides provide evidence for the trend in reactivity in Group 7

Explain the trend in reactivity in Group 7 in terms of electronic configurations

Know the approximate percentages by volume of the four most abundant gases in dry air

Understand how to determine the percentage by volume of oxygen in air using experiments involving the reactions of metals (e.g. iron) and non-metals (e.g. phosphorus) with air

Describe the combustion of elements in oxygen, including magnesium, hydrogen and sulfur

Describe the formation of carbon dioxide from the thermal decomposition of metal carbonates, including copper(II) carbonate

Know that carbon dioxide is a greenhouse gas and that increasing amounts in the atmosphere may contribute to climate change

Practical: determine the approximate percentage by volume of oxygen in air using a metal or a non-metal

Understand how metals can be arranged in a reactivity series based on their reactions with: • water • dilute hydrochloric or sulfuric acid.

Understand how metals can be arranged in a reactivity series based on their displacement reactions between: • metals and metal oxides • metals and aqueous solutions of metal salts.

Know the order of reactivity of these metals: potassium, sodium, lithium, calcium, magnesium, aluminium, zinc, iron, copper, silver, gold

Know the conditions under which iron rusts

Understand how the rusting of iron may be prevented by: • barrier methods • galvanising • sacrificial protection.

Understand the terms: • oxidation • reduction • redox • oxidising agent • reducing agent in terms of gain or loss of oxygen and loss or gain of electrons.

Practical: investigate reactions between dilute hydrochloric and sulfuric acids and metals (e.g. magnesium, zinc and iron)

Know that most metals are extracted from ores found in the Earth’s crust and that unreactive metals are often found as the uncombined element

Explain how the method of extraction of a metal is related to its position in the reactivity series, illustrated by carbon extraction for iron and electrolysis for aluminium

Be able to comment on a metal extraction process, given appropriate information detailed knowledge of the processes used in the extraction of a specific metal is not required

Explain the uses of aluminium, copper, iron and steel in terms of their properties the types of steel will be limited to low-carbon (mild), high-carbon and stainless

Know that an alloy is a mixture of a metal and one or more elements, usually other metals or carbon

Explain why alloys are harder than pure metals

Describe the use of litmus, phenolphthalein and methyl orange to distinguish between acidic and alkaline solutions

Understand how to use the pH scale, from 0-14, can be used to classify solutions as strongly acidic (0-3), weakly acidic (4-6), neutral (7), weakly alkaline (8-10) and strongly alkaline (11-14)

Describe the use of universal indicator to measure the approximate pH value of an aqueous solution

Know that acids in aqueous solution are a source of hydrogen ions and alkalis in a aqueous solution are a source of hydroxide ions

Know that alkalis can neutralise acids

Describe how to carry out an acid-alkali titration

Know the general rules for predicting the solubility of ionic compounds in water: • common sodium, potassium and ammonium compounds are soluble • all nitrates are soluble • common chlorides are soluble, except those of silver and lead(II) • common sulfates are soluble, except for those of barium, calcium and lead(II) • common carbonates are insoluble, except for those of sodium, potassium and ammonium • common hydroxides are insoluble except for those of sodium, potassium and calcium (calcium hydroxide is slightly soluble).

Understand acids and bases in terms of proton transfer

Understand that an acid is a proton donor and a base is a proton acceptor

Describe the reactions of hydrochloric acid, sulfuric acid and nitric acid with metals, bases and metal carbonates (excluding the reactions between nitric acid and metals) to form salts

Know that metal oxides, metal hydroxides and ammonia can act as bases, and that alkalis are bases that are soluble in water

Describe an experiment to prepare a pure, dry sample of a soluble salt, starting from an insoluble reactant

Describe an experiment to prepare a pure, dry sample of a soluble salt, starting from an acid and alkali

Describe an experiment to prepare a pure, dry sample of an insoluble salt, starting from two soluble reactants

Practical: prepare a sample of pure, dry hydrated copper(II) sulfate crystals starting from copper(II) oxide

Practical: prepare a sample of pure, dry lead(II) sulfate

2.44Gas tests

Describe tests for these gases: • hydrogen • oxygen • carbon dioxide • ammonia • chlorine.

2.45Flame-test method

Describe how to carry out a flame test

2.46Flame-test colours

Know the colours formed in flame tests for these cations: • Li+ is red • Na+ is yellow • K+ is lilac • Ca2+ is orange-red • Cu2+ is blue-green.

2.47Cation tests

Describe tests for these cations: • NH4+ using sodium hydroxide solution and identifying the gas evolved • Cu2+, Fe2+ and Fe3+ using sodium hydroxide solution.

2.48Anion tests

Describe tests for Cl⁻, Br⁻ and I⁻ using acidified silver nitrate; SO₄²⁻ using acidified barium chloride; and CO₃²⁻ using hydrochloric acid and identification of the evolved gas.

2.49Test for water

Describe a test for the presence of water using anhydrous copper(II) sulfate

2.50Water purity test

Describe a physical test to show whether a sample of water is pure