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Unit 2: Energy, Rate and Chemistry of Carbon Compounds

7 dot points across 7 inquiry questions. Click any dot point for a focused answer with worked past exam questions where available.

How are alcohols and carboxylic acids made and how do they react?

Classification and oxidation of alcohols, dehydration and esterification, the reactions of carboxylic acids, and the preparation and hydrolysis of esters.
A focused answer to WJEC A-Level Chemistry Unit 2, covering primary, secondary and tertiary alcohols and their oxidation, dehydration to alkenes, esterification, the acidity and reactions of carboxylic acids, and ester hydrolysis.
12 min answer →

How do halogenoalkanes react and how does their structure affect rate?

Nucleophilic substitution and elimination of halogenoalkanes, the effect of carbon-halogen bond strength on rate, and the environmental impact of CFCs on the ozone layer.
A focused answer to WJEC A-Level Chemistry Unit 2, covering nucleophilic substitution and elimination of halogenoalkanes, how carbon-halogen bond strength controls reactivity, and the role of CFCs in ozone depletion.
11 min answer →

How do alkanes and alkenes react and why?

Alkanes and alkenes, free-radical substitution, electrophilic addition, Markovnikov addition, addition polymerisation, and combustion.
A focused answer to WJEC A-Level Chemistry Unit 2, covering alkanes and alkenes, free-radical substitution, electrophilic addition with Markovnikov's rule, addition polymerisation, and the combustion of hydrocarbons.
12 min answer →

How do we name and represent organic molecules?

Functional groups, homologous series, IUPAC nomenclature, structural and displayed formulae, structural and E/Z isomerism, and reaction mechanism notation.
A focused answer to WJEC A-Level Chemistry Unit 2, covering functional groups and homologous series, IUPAC nomenclature, structural, displayed and skeletal formulae, structural and E/Z isomerism, and the curly-arrow notation for mechanisms.
11 min answer →

What controls how fast a reaction goes?

Collision theory, activation energy, the effect of concentration, temperature, surface area and catalysts on rate, and the Maxwell-Boltzmann distribution.
A focused answer to WJEC A-Level Chemistry Unit 2, covering collision theory and activation energy, the effects of concentration, temperature, surface area and catalysts, and how the Maxwell-Boltzmann distribution explains the temperature effect.
11 min answer →

How does chemistry affect society, the economy and the environment?

Green chemistry, atom economy and percentage yield, sustainable feedstocks and energy, the carbon footprint of processes, and the social and economic impact of chemical manufacture.
A focused answer to WJEC A-Level Chemistry Unit 2, covering green chemistry principles, atom economy and percentage yield, sustainable feedstocks and renewable energy, carbon footprint, and the social and economic impact of chemical manufacture.
11 min answer →

Where does the energy of a reaction come from and how is it measured?

Enthalpy changes, exothermic and endothermic reactions, calorimetry, standard enthalpies of formation and combustion, Hess's law and bond enthalpies.
A focused answer to WJEC A-Level Chemistry Unit 2, covering enthalpy changes, exothermic and endothermic reactions, calorimetry, standard enthalpies of formation and combustion, Hess's law cycles and bond-enthalpy calculations.
12 min answer →