a) (1) C2H6 \(\underrightarrow{t^o,xt}\) C2H4 + H2
(2) nCH2 = CH2
b) (1) 2CH4 \(\underrightarrow{1500^oC}\) C2H2 + 3H2
(2) 2CH ≡ CH \(\underrightarrow{t^o,xt}\) CH2 = CH – C ≡ CH
(3) CH2 = CH – C ≡ CH + H2 \(\xrightarrow[t^o]{Pd\text{/}PbCO_3}\) CH2 = CH – CH = CH2
(4) nCH2 = CH – CH – CH2
c) + Br + HBr.