8.
通过乙醇制取氢气通常有如下两条途径:
\(\rm{a.CH_{3}CH_{2}OH(g)+H_{2}O(g)=4H_{2}(g)+2CO(g)}\) \(\rm{Δ}\)\(\rm{H}\)\(\rm{{\,\!}_{1}=+256.6 kJ·mol^{-1}}\)
\(\rm{b.2CH_{3}CH_{2}OH(g)+O_{2}(g)=6H_{2}(g)+4CO(g)}\) \(\rm{Δ}\)\(\rm{H}\)\(\rm{{\,\!}_{2}=+27.6 kJ·mol^{-1}}\)
则下列说法正确的是