Chemistry

Aspects of carbon chemistry will be selected from the following:

• Structure – names of carbon compounds using systematic nomenclature – structural formulae – covalent bonding between atoms.
• Properties – solubility in water – trends in melting and/or boiling points – complete and incomplete combustion reactions – polymerisation reactions of ethene and propene.
• Production – fractional distillation of crude oil – cracking of fractions – fermentation – methanol from natural gas.
• Uses and importance – fuels – polymers from ethene and propene.
• Effects of combustion products on human health and the environment.

Carbon compounds are restricted to:

• Straight chain alkanes, ethene and propene, methanol and ethanol.
• Structures and names of alkanes are limited to alkanes which contain no more than eight carbon atoms.

Investigate involves carrying out a range of chemical reactions and recording observations and classifying reactions.

Investigating the chemical reactions also include giving an account of selected chemical reactions and using solubility rules to determine solubility. This requires the use of chemistry vocabulary, symbols and conventions (including names and formulae), and writing word equations.

For Merit also include:

• classifying chemical reactions from experimental observations and/or equations and
• predicting the formation of a precipitate using solubility rules and
• completing symbol equations.

For Excellence also include:

• explaining and justifying the links between the classification of reactions, observations and equations, and
• explaining and justifying the formation of precipitates and solubility rules,
• writing balanced symbol equations.

Chemical reactions will be selected from:

• Combination reactions. These are limited to simple reactions of elements with other elements (such as magnesium or sulphur with oxygen, iron with sulphur etc).
• Exchange reactions. These are limited to precipitation reactions such as the formation of: chlorides of silver and lead; sulfates of barium and lead; hydroxides of copper, iron(II), calcium, and magnesium; carbonates of copper, iron(II), zinc, calcium, and magnesium.
• Decomposition reactions. These are limited to thermal decomposition of carbonates and hydrogen carbonates.
• Displacement reactions. These are limited to the displacement of metal ions in solution by other metals.