AS and A2 Chemistry notes and resources (WJEC specification) - UNIT CH2. Properties, Structure and Bonding

The uses to which materials can be put depend on their properties, which in turn depend on the bonding and structure within the material. By understanding the relationship between these factors, chemists are able to design new materials. The types of forces that can exist between particles are studied, along with several types of solid structures, in order to illustrate how these factors influence properties. The building blocks of materials are the elements and the relationship of their properties to their position in the Periodic Table is illustrated by a study of the elements of the s-block and Group 7. An introduction to organic chemistry provides the basis for an understanding of how the properties of carbon compounds can be modified by the introduction of functional groups.

7.1 - Organic compounds and their reactions

Candidates should be able to:

(a) write displayed, shortened and skeletal structural formulae of simple alkanes, alkenes, halogenoalkanes, primary alcohols and carboxylic acids given their systematic names, and vice versa;

(b) describe the effect of increasing hydrocarbon chain length and of the above functional groups on physical properties, melting and boiling temperature and solubility;

(c) describe structural isomerism and be able to write down the structural isomers of noncyclic organic compounds (up to and including C6 homologues) including those of different chemical class;

(d) describe E-Z isomerism in alkenes, give an example, and discuss such isomerism in terms of restricted rotation about the C = C bond, and appreciate that E-Z isomers may have different physical and chemical properties;

(e) derive empirical formulae from elemental composition data and use such results, together with additional data, to deduce molecular formulae;

(f) identify reactants as electrophilic, nucleophilic or radical in type, explain the basis of this classification, and give examples of each;

(g) classify the following types of functional group reactions and describe their nature: electrophilic addition, elimination, oxidation, hydrolysis;

(h) describe the total oxidation of primary alcohols, RCH2OH, to carboxylic acids, RCOOH. (Knowledge of the properties of aldehydes is not, at this stage, required);

(i) recognise the following functional group tests by the indicated reactions: C = C addition of Br2(aq); .X (Cl, Br, I ) hydrolysis by aqueous base, followed by reaction with AgNO3(aq) / HNO3(aq).