How to write a chemical reaction with tabs in formula LaTeX

Question

I would like to produce this formula in LaTeX. I have tried the following, but I don't know how to centre the first equation (reaction) and to move the parenthesis part le right side of the page. Can someone maybe help with this?

\begin{equation}
  CO_{2}+ 3H_2 \longleftrightarrow CH_{3}OH + H_{2}O 
  \hspace{5cm} 
  \left[ \delta H_{o}^{R} = -90.8 \frac{kJ}{mol}\right]
\end{equation}

Answer 1

Use dedicated packages for

1. math,
2. chemical formulas,
3. typesetting of physical quantities.

Don't move the parts in brackets to the right margin.

\documentclass{article}
\usepackage{amsmath}
\usepackage{array}
\usepackage{chemformula}
\usepackage{siunitx}

\begin{document}

\begin{equation*}
\sisetup{per-mode=fraction}
\begin{array}{@{} c @{\hspace{4em}} >{\displaystyle}l @{}}
\ch{CO + 2 H2 <-> CH2OH} & \biggl[\Delta H_0^R = \qty{-90.8}{\kilo\joule\per\mol}\biggr]
\\[3ex]
\ch{CO2 + 3 H2 <-> CH_3OH + H2O} & \biggl[\Delta H_0^R = \qty{-49.6}{\kilo\joule\per\mol}\biggr]
\end{array}
\end{equation*}

\end{document}

If you need to number the equations, you can use IEEEeqnarray.

\documentclass{article}
\usepackage{amsmath}
\usepackage{array}
\usepackage{chemformula}
\usepackage{siunitx}
\usepackage{IEEEtrantools}

\sisetup{per-mode=fraction}

\begin{document}

\begin{IEEEeqnarray}{c"l}
\ch{CO + 2 H2 <-> CH2OH} & \biggl[\Delta H_0^R = \qty{-90.8}{\kilo\joule\per\mol}\biggr]
\\
\ch{CO2 + 3 H2 <-> CH_3OH + H2O} & \biggl[\Delta H_0^R = \qty{-49.6}{\kilo\joule\per\mol}\biggr]
\end{IEEEeqnarray}

\end{document}

Answer 2

I would like to suggest that you (a) use a chemistry package, such as mhchem, to typeset chemical formulas, (b) employ the amsmath package and its gather environment to typeset the two-row material in display math mode, (c) use a package such as siunitx to typeset quantities and their associated scientific units, and (d) employ the \tag* macro (also provided by the amsmath package) to typeset the "tags" at the far right hand side of each row.

\documentclass{article}
\documentclass{article}
\usepackage{amsmath} % for 'gather' env. and '\tag*' macro
\usepackage{mhchem}  % for '\ce' macro
\usepackage{siunitx} % for '\qty' macro
\sisetup{per-mode = fraction,
         output-decimal-marker = {,}}        

\begin{document}

\begin{gather*}
\ce{CO + 2H2 <-> CH3OH}
  \tag*{$\left[ \Delta H_{o}^{R} = 
    \qty{-90.8}{\kilo\joule\per\mol}\right]$} \\[\jot]
\ce{CO2 + 3H2 <-> CH3OH + H2O}
  \tag*{$\left[ \Delta H_{o}^{R} = 
    \qty{-49.6}{\kilo\joule\per\mol}\right]$} 
\end{gather*}

\end{document}

Answer 3

I used the align* command, but the reactions are not centered, they are aligned with the arrows.

The arrow <-> is used for an ion in resonance, use the common arrow ->

\documentclass[12pt]{article}
\usepackage[version=4]{mhchem}
\usepackage{amsmath}
\begin{document}

\begin{align*}
    \ce{CO + H2} & \ce{-> CH3OH} & \hspace{5cm}  \left[  \delta H_{o}^{R} =   -90.8 \frac{kJ}{mol}  \right]  \\
    \ce{CO2 + 3H2} & \ce{-> CH3OH + H2O}  & \hspace{5cm}  \left[ \delta H_{o}^{R} = -49.6 \frac{kJ}{mol}\right]  \\
\end{align*}
\end{document}