a)
\(2C{H_4}\xrightarrow{{{{1500}^o}C}}{C_2}{H_2} + 3{H_2}\)
\({C_2}{H_2} + {H_2}\xrightarrow{{{t^o},Pd}}{C_2}{H_4}\)
\({C_2}{H_4} + {H_2}O\xrightarrow{{{H_2}S{O_4},{t^o}}}{C_2}{H_5}OH\)
b)
\(2{C_2}{H_2}\xrightarrow{{{t^o}}}CH \equiv C - CH = C{H_2}\)
\(CH \equiv C - CH = C{H_2} + {H_2}\xrightarrow{{Pd,{t^o}}}C{H_2} = CH - CH = C{H_2}\)
\(nC{H_2} = CH - CH = C{H_2}\xrightarrow{{{t^o},xt}}{( - C{H_2} - CH = CH - C{H_2} - )_n}\)