[Tex/LaTex] Chemical equation with heat of formation

mhchem

I'm new to Latex and I'm having some trouble with a simple chemical equation.
I have the following code:

\documentclass{article}
\usepackage[version=3]{mhchem} % Package for chemical equation typesetting
\usepackage{amssymb}

\begin{document}
\begin{equation} \ce{N2(g) + 3H2(g) -> 2NH3(g)}} \end{equation}  
$\Delta H_{\mathrm{f}}^\circ = \SI{-92.5}{kJ}$
\end{document}

This prints everything that I need, but on separate lines. I would just like the heat of formation (deltaH=-92.5kj) to be inline with the equation. I've tried multiple approaches, but keep getting stuck. I haven't seen this discussed on TEX or elsewhere.

Best Answer

You can simply write it inside the equation and maybe add some horizontal space between with \quad or \qquad:

\documentclass{article}
\usepackage[version=4]{mhchem} % Package for chemical equation typesetting
\usepackage{amssymb}
\usepackage{siunitx}
\begin{document}

\begin{equation}
  \ce{N2(g) + 3H2(g) -> 2NH3(g)} \qquad \Delta H_{\mathrm{f}}^\circ = \SI{-92.5}{kJ}
\end{equation}  

\end{document}

enter image description here

An alternative using chemmacros:

\documentclass{article}

\usepackage{chemmacros}
\chemsetup{
  formula = chemformula , % or mhchem
  modules = thermodynamics
}

\begin{document}

\begin{equation}
  \ch{N2\gas{} + 3 H2\gas{} -> 2 NH3\gas} \qquad \enthalpy(f){-92.5}
\end{equation}  

\end{document}

enter image description here

For a non-molar heat of formation it would let you easily define a command \formation:

\documentclass{article}

\usepackage{chemmacros}
\chemsetup{
  formula = chemformula , % or mhchem
  modules = thermodynamics
}

\NewChemState\formation{
  symbol = H ,
  subscript =f ,
  unit = \kilo\joule
}

\begin{document}

\begin{equation}
  \ch{N2\gas{} + 3 H2\gas{} -> 2 NH3\gas} \qquad \formation{-92.5}
\end{equation}  

\end{document}

enter image description here

There are a number of options for customization (e.g. regarding the position of the subscript).

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