Alkanes, in the gaseous state, will react with oxygen in highly exothermic reactions. Methane burns in oxygen to release energy and produce carbon dioxide and water. The reaction is shown on the right.

CH4(g) + 2O2(g) => CO2(g) + 2H2O(l) 

Under the right conditions, alkanes undergo substitution reactions. During such reactions atoms or groups of atoms are replaced by other atoms or groups. For example, in the production of chloroethane, a hydrogen is replaced by a chlorine atom. If chlorine is plentiful further hydrogen atoms are replaced. During this substitution reaction hydrogen chloride is produced.

This may not be the exact mechanism for this reaction.

Further substitution can occur. For example, bubbling chloromethane gas through a solution containing sodium hydroxide will produce methanol. As seen on the right, the chlorine atom is substituted for an alcohol group (OH).

Using an electron dot diagram explain why a reaction between methane and chlorine gas can not produce the compound CH4Cl2 as specified in the chemical equation below.

CH4 + Cl2 => CH4Cl2

Is CH4 less soluble in water than CH3OH? Explain.

Compare the properties of ethane and ethanol.