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Cover Making the Transition to University Chemistry

Hydrocarbons: Alkanes  

This chapter tackles the concept of alkanes, a type of hydrocarbon. It defines a hydrocarbon as containing hydrogen and carbon only. Alkanes are saturated hydrocarbons. Crude oil is an example of a complex mixture of hydrocarbons, most of which are alkanes. Fractional distillation allows for the separation of the mixture and relies on the different fractions with varying boiling points. The chapter explores the mechanism for radical chain reaction and photochemical halogenation which occur through the reaction of an alkane with a halogen. Finally, the combustion of alkanes is considered to be the most significant reaction commercially since it is also a radical chain reaction.


Cover Atkins’ Physical Chemistry

Phase diagrams of binary systems: liquids  

This chapter focuses on phase diagrams of systems of liquids. It begins by looking at vapour pressure diagrams. The partial vapour pressures of the components of an ideal mixture of two volatile liquids are related to its composition by Raoult's law. The chapter then considers temperature–composition diagrams, in which the boundaries show the composition of the phases that are in equilibrium at various temperatures. The lever rule is used to deduce the relative abundances of each phase in equilibrium. The chapter also discusses how the separation of a liquid mixture by fractional distillation involves repeated cycles of boiling and condensation. An azeotrope is a liquid mixture that boils without change of composition. Finally, the chapter examines liquid–liquid phase diagrams.


Cover The Basis and Applications of Heterogenuous Catalysis

Raw materials and their conversion  

This chapter addresses raw materials and their conversion. The major volume sources of chemicals are coal, oil, and natural gas. The chapter then details the pattern of feedstock conversion and the products formed. If we begin with the main carbon source for the petrochemical industry, crude oil, then the first process is separation of the fractions of light molecules, intermediates (naphtha), and heavier fractions. This is achieved by fractional distillation. The most useful molecules for chemical synthesis and for fuel are produced by catalytic cracking of the higher chain length alkenes. Ultimately, synthesis gas is obtained which can be used for a wide range of products.