Deduce the molecular formula of the alkene which has a relative molecular mass of $168$. 

All hydrocarbons are covalently bonded whether saturated or unsaturated. Draw 'dot-and-cross' diagrams for methane and ethane illustrating the arrangement of the bonding electrons. You only need to draw the outer electrons of the carbon atoms. 

The table shows the formulae of the first three members of the alcohol homologous series.

Use the information given to deduce the general formula for the alcohol homologous series. 

Ethanol, the most significant of the alcohols can be manufactured from either ethene or glucose. Write an equation for the industrial production of ethanol from ethene and state the conditions under which the reaction takes place. 

Complete the following table. (Relative atomic masses: $\mathrm{H}=1, \mathrm{C}=12$.) 

Butane is the alkane which contains four carbon atoms in each molecule. Draw the structural formula of butane and of an isomer of butane.