接触法制硫酸工艺三个步骤中的热化学方程式如下：

\(\rm{①4FeS_{2}(s)+11O_{2}(g)=2Fe_{2}O_{3}(s)+8SO_{2}(g)}\)    \(\rm{Δ}\)\(\rm{H}\)\(\rm{{\,\!}_{1}=—3412 kJ·mol^{-1}}\)

\(\rm{②2SO_{2}(g)+O_{2}(g)=2SO_{3}(g)}\)                \(\rm{Δ}\)\(\rm{H}\)\(\rm{{\,\!}_{2}=—196.6 kJ·mol^{-1}}\)

\(\rm{③SO_{3}(g)+H_{2}O(l)=H_{2}SO(l)}\)              \(\rm{Δ}\)\(\rm{H}\)\(\rm{{\,\!}_{3}=—130.3 kJ·mol^{-1}}\)