CHEMISTRY BSTUDY AREA 3: ORGANIC CHEMISTRYPART 2: ISOMERISM AND HYDROCARBON (ALKANES)Learning outcomes: Use chemical equations to describe the oxidation of alkanes Identify members of the alkanes and alkenes homologous series Compare and contrast chemical properties of alkanes and alkenes Describe physical properties of alkanes and alkenes Definitions A hydrocarbon is an organic compound which contains carbon and hydrogen atoms only A functional group is an atom or group of atoms which determine the chemical properties of the organic compound Homologous series is a family of compounds with the same general molecular formula and same functional group(refer to Part 2: Naming Organic Compounds for grouping)

ALKANES General molecular formula: Cn H 2n + 2 Saturated hydrocarbon Functional group : CC single bonds Generally unreactive due to high bond energies of C-H and C-C bonds and lack of polarity Only 2 chemical reactions: Combustion with oxygen Free radical substitution with halogen ( brief knowledge of mechanism is required)

Structure of ethane

Structures of first 3 alkanes

Complete combustion of alkanesCH4 (g) + 2O2 (g) CO2 (g) + 2H20 (l)

Free radical substitution of alkanesCH4 + Cl2 CH3Cl + HClCH3Cl + Cl2 CH2Cl2 + HClCH2Cl2 + Cl2 CHCl3 + HClCHCl3 + Cl2 CCl4 + HCl

GRADUAL CHANGES IN PHYSICAL PROPERTIES