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Northern IrelandCombined Science

C2 Further Reactions, Rates, Organic Chemistry and Calculations

8 dot points across 8 inquiry questions. Click any dot point for a focused answer with worked past exam questions where available.

What are alcohols, how is ethanol made, and how do alkenes form polymers?

Alcohols as a homologous series with the OH functional group, the production of ethanol by fermentation and by hydration of ethene, addition polymerisation of alkenes, drawing the repeating unit, and the problems of plastic disposal.
A focused CCEA GCSE Double Award Science (Chemistry Unit C2) answer on alcohols and polymers, covering alcohols and the OH group, making ethanol by fermentation and by hydration of ethene, addition polymerisation of alkenes, the repeating unit, and plastic disposal.
8 min answer →

How do we measure concentration, find an unknown concentration by titration, and work out percentage yield?

Concentration in g per dm cubed and mol per dm cubed, using titration results to find an unknown concentration, and calculating percentage yield.
A focused CCEA GCSE Double Award Science (Chemistry Unit C2) answer on quantitative chemistry, covering concentration in g per dm cubed and mol per dm cubed, using titration results to find an unknown concentration, and calculating percentage yield.
8 min answer →

What is crude oil, how is it separated, and what are alkanes, alkenes and cracking?

Crude oil as a mixture of hydrocarbons separated by fractional distillation, how the properties of fractions change with chain length, alkanes and alkenes as saturated and unsaturated hydrocarbons, the bromine water test, and cracking.
A focused CCEA GCSE Double Award Science (Chemistry Unit C2) answer on crude oil and hydrocarbons, covering fractional distillation, how fraction properties change with chain length, alkanes and alkenes, the bromine water test for unsaturation, and cracking.
8 min answer →

What is electrolysis, and how do we predict the products at each electrode?

Electrolysis of molten ionic compounds and of aqueous solutions including brine, predicting the products formed at the cathode and anode, and writing electrode half-equations.
A focused CCEA GCSE Double Award Science (Chemistry Unit C2) answer on electrolysis, covering the electrolysis of molten ionic compounds and aqueous solutions including brine, predicting the products at the cathode and anode, and writing electrode half-equations.
8 min answer →

Why do reactions give out or take in heat, and how do we measure it?

Exothermic and endothermic reactions, energy level diagrams, and measuring temperature changes using calorimetry to compare the energy released by fuels.
A focused CCEA GCSE Double Award Science (Chemistry Unit C2) answer on energy changes, covering exothermic and endothermic reactions, energy level diagrams, activation energy, and measuring temperature changes using calorimetry to compare fuels.
8 min answer →

What controls how fast a reaction goes, and how does collision theory explain it?

The factors that affect the rate of reaction (concentration, temperature, surface area and catalysts), how rate is measured, collision theory and activation energy, and how each factor changes the frequency or energy of collisions.
A focused CCEA GCSE Double Award Science (Chemistry Unit C2) answer on reaction rates, covering the factors that affect rate, how rate is measured by gas volume or mass loss, collision theory and activation energy, and how catalysts and the other factors change collisions.
8 min answer →

How do we rank metals by reactivity, and how does this decide how they are extracted?

The reactivity series of metals, the reactions of metals with water and acid, displacement reactions, oxidation and reduction in terms of oxygen and electrons, and how reactivity determines the method of extracting a metal from its ore.
A focused CCEA GCSE Double Award Science (Chemistry Unit C2) answer on metals, covering the reactivity series, reactions with water and acid, displacement reactions, oxidation and reduction in terms of oxygen and electrons, and how reactivity decides the method of extraction.
8 min answer →

What is a reversible reaction, and how is the Haber process used to make ammonia?

Reversible reactions and dynamic equilibrium, how changing conditions shifts the position of equilibrium, and the conditions used in the Haber process to make ammonia for fertilisers.
A focused CCEA GCSE Double Award Science (Chemistry Unit C2) answer on reversible reactions, covering dynamic equilibrium, how changing temperature, pressure and concentration shift the equilibrium, and the conditions used in the Haber process to make ammonia.
8 min answer →