2. After completing this topic you should be able to : State the cycloalkanes are another homologous series and write the general formula. State the physical and chemical properties of the cycloalkanes. Describe how physical properties (melting point, boiling point, rate of evaporation, viscosity) and chemical properties ( flammability and smokiness of flame) relates to the size of molecule. Give some uses of cycloalkanes.

3. C H C C H H H H H C3H6C3H6 Carbons atoms are joined in a ring. Molecule has 3 carbon atoms. All the carbon to carbon bonds are single (C-C).

4. Write the names, full structural formulae, shortened structural formula and molecular formula of each cycloalkane with 4 to 6 carbon atoms. Write the names, full structural formulae, shortened structural formula and molecular formula of each cycloalkane with 4 to 6 carbon atoms. GENERAL FORMULA FOR CYCLOALKANES C n H 2n n = 3, 4, 5, ………. GENERAL FORMULA FOR CYCLOALKANES C n H 2n n = 3, 4, 5, ………. H C C C C H H H H H H H H C C C C H H H H H H H C H H H C C C C H H H H H H H C H H C H H cyclobutane C 5 H 10 cyclohexane C4H8C4H8 cyclopentane C 6 H 12

5. PROPERTY TESTEDCYCLOHEXANE Appearance (colour and state) Smell Flammability Solubilty in water pH (acidic / neutral / alkaline?) Effect on bromine solution Colourless liquid Strong Very flammable smokey flame Immiscible Neutral Remains orange Cycloalkanes have similar properties to alkanes.

6. Write the WORD and BALANCED FORMULA EQUATION for the combustion of cyclohexane. cyclohexaneoxygenwater carbon dioxide ++ + +C 6 H 12 O2O2 H2OH2OCO 2 6 6 9 The physical properties of the molecules in a homologous series all change as the number of carbon atoms in the molecules increase. The melting and boiling points, the viscosity of the alkanes, alkenes and cycloalkanes all show an increase going up the series as the number of carbon atoms in their molecules increase.