Describe two methods of preparaton of ethane. Given any three reaction of ethane.

Explanation

A. Methods of preparation of ethane.
(1). Decarboxylation of sodium propionate: Ethane is preapared by heating sodium propionate with soda lime. (Soda lime=NaOH+CaO) `CH_(3)-CH_(2)-COONa+NaOH underset(Delta)overset(CaO)to C_(2)H_(6)+Na_(2)CO_(3)`
Wurtz reaction: Ethane is prepared by heating methyl iodide with sodium metal is dry ether.
`CH_(3)I+2Na+ICH_(3) underset("ether")overset("Dry")to CH_(3)-CH_(3)+2NaI`
Properties of ethane:
1. Substitution reactions: Reaction is which an atom or group present in a compound is replaced by another atom or group are known as substitutio reactions.
(a) Halogenation: In the presence of sunlight or UV radiation ethane undergoes halogenation. The H atoms of alkane are successively replaced by halogens atoms.
`C_(2)H_(6) underset(Cl_(2))overset(hv)to C_(2)H_(5)Cl underset(Cl_(2))overset(hv)to C_(2)H_(4)Cl_(2) underset(Cl_(2))overset(hv)to C_(2)H_(3)Cl_(3) underset(Cl_(2))overset(hv)to C_(2)H_(2)Cl_(4) underset(Cl_(2))overset(hv)to C_(2)HCl_(5) underset(Cl_(2))overset(hv)to C_(2)Cl_(6)`
(b) Nitration: Ethane reacts with vapours of `HNO_(3) at 400^(@)C` and forms nitroethane.
`C_(2)H_(6)+HNO_(3) overset(400^(@)C)to C_(2)H_(5)NO_(2)+H_(2)O`
Combustion : Complete oxidation of th compared in air is called 'combustion'. It gives `CO_(2) and H_(2)O` along with liberation of heat.
`C_(2)H_(6)+7/2O_(2) to 2CO_(2)+3H_(2)O+"energy"`