Giải bài 3 trang 172 SGK Hóa học 11

$\begin{align} & a)\\&C{{H}_{3}}-C{{H}_{3}}\xrightarrow{{{500}^{o}}C}C{{H}_{2}}=C{{H}_{2}}+{{H}_{2}} \\ & nC{{H}_{2}}=C{{H}_{2}}\xrightarrow[p,xt]{{{t}^{o}}}{{(-C{{H}_{2}}-C{{H}_{2}}-)}_{n}} \\ & b)\\&2C{{H}_{4}}\xrightarrow[làm\,lạnh\,nhanh]{{{1500}^{o}}C}CH\equiv CH+3H_2 \\ & 2CH\equiv CH\xrightarrow[{{450}^{o}}C]{CuCl,N{{H}_{4}}Cl}C{{H}_{2}}=CH-C=C{{H}_{}} \\ &CH_2=CH-C\equiv CH+H_2\xrightarrow[Pd/PbCO_3]{{{t}^{o}}}CH_2=CH-CH=CH_2\\ & nC{{H}_{2}}=CH-CH=C{{H}_{2}}\xrightarrow[Na]{{{t}^{o}},p}{{(-C{{H}_{2}}-CH=CH-C{{H}_{2}}-)}_{n}} \\ \end{align}$