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.

4.4 - Solubility of compounds in water

Candidates should be able to:

(a) use a simple model to explain the ability of certain solutes to dissolve in water either by virtue of hydrogen bonding or dipolar forces and apply this to explain the solubility of ethanol and sodium chloride, and the insolubility (immiscibility) of hydrocarbons, in water;

(b) understand and use solubility both qualitatively and quantitatively (i.e. in terms of mass or moles per unit volume) and understand the recovery of soluble salts from aqueous solution by crystallisation.