LaTeX forum ⇒ Math & Science ⇒ Using tabular/array with chemical equations

[ghostanime2001]

How can I set the plus signs and right arrow on the last line align between the masses (46 g + 36 g --> 80 g + 2 g) AND align vertically with the plus and right arrow on the first line? This is the closest to what I can get please see the latex code... And yes this is my minimal example believe me.. I've got a huge table with many more equations.

Code: [Select all] [Expand/Collapse] [Download] (untitled.tex)

\documentclass[fleqn]{article}
\usepackage{amsmath}   
\usepackage[version=3]{mhchem}
\usepackage{chemmacros}
\begin{document}
$\begin{tabular}[t]{@{}lllllllll}
\ce{$\underset{\begin{tabular}{@{}c@{}}2 molecules \\ 2 mols \\ 2(23) \\ 46g\end{tabular}}{\ce{2Na_{(s)}}}$}&+&\ce{$\underset{\begin{tabular}{@{}c@{}}2 molecules \\ 2 mols \\ 2(18) \\ 36g\end{tabular}}{\ce{2H2O_{(l)}}}$}&\ce{->}&\ce{$\underset{\begin{tabular}{@{}c@{}}2 molecules \\ 2 mols \\ 2(40) \\ 80g\end{tabular}}{\ce{2NaOH_{(aq)}}}$}&+&\ce{$\underset{\begin{tabular}{@{}c@{}}1 molecule \\ 1 mol \\ 2 \\ 2g\end{tabular}}{\ce{H2\gas{}}}$} \\
&+&&\ce{->}&&+&
\end{tabular}$
\end{document}

[ghostanime2001]

Anyone?

[justdeath]

You write tabular a little strangely. Here is my tabular:

Code: [Select all] [Expand/Collapse] [Download] (untitled.tex)

\documentclass[fleqn]{article}
\usepackage{amsmath}   
\usepackage[version=3]{mhchem}
\usepackage{chemmacros}
 
\begin{document}
\begin{tabular}{*{7}{c}}
\ce{2 Na_{(s)}} & + & \ce{2H2O_{(l)}} & $\longrightarrow$ & \ce{2NaOH_{(aq)}} & + & \ce{H2\gas{}} \\
2 molecules & & 2 molecules & & 2 molecules & & 1 molecule \\
2 mols & & 2 mols & & 2 mols & & 1 mol \\
2(18) & & 2(22) & & 2(40) & & 2 \\
46g & + & 36g & $\longrightarrow$ & 80g & + & 2g
\end{tabular}
\end{document}

Nikolay

[ghostanime2001]

I'd like to keep the \underset and tabular environment in my code. I am looking for minor tweak if there is one which will allow me to do what you did.

[justdeath]

This is the closest I can get:

Code: [Select all] [Expand/Collapse] [Download] (untitled.tex)

\documentclass[fleqn]{article}
\usepackage{amsmath}   
\usepackage[version=3]{mhchem}
\usepackage{chemmacros}
 
\begin{document}
$\begin{tabular}[t]{@{}lllllllll}
\ce{$\underset{\begin{tabular}{@{}c@{}}2 molecules \\ 2 mols \\ 2(23) \\ 46g\end{tabular}}{\ce{2Na_{(s)}}}$}&
\ce{$\underset{\begin{tabular}{@{}c@{}} \\ \\ \\ + \end{tabular}}+$}&
\ce{$\underset{\begin{tabular}{@{}c@{}}2 molecules \\ 2 mols \\ 2(18) \\ 36g\end{tabular}}{\ce{2H2O_{(l)}}}$}&
\ce{$\underset{\begin{tabular}{@{}c@{}} \\ \\ \\ $\longrightarrow$ \end{tabular}}\longrightarrow$}&
\ce{$\underset{\begin{tabular}{@{}c@{}}2 molecules \\ 2 mols \\ 2(40) \\ 80g\end{tabular}}{\ce{2NaOH_{(aq)}}}$}&
\ce{$\underset{\begin{tabular}{@{}c@{}} \\ \\ \\ + \end{tabular}}+$}&
\ce{$\underset{\begin{tabular}{@{}c@{}}1 molecule \\ 1 mol \\ 2 \\ 2g\end{tabular}}{\ce{H2\gas{}}}$}
\end{tabular}$
\end{document}

And the signs on the last row are aligned vertically, but not horizontally (with the masses).

Nikolay

[ghostanime2001]

hmmmm.... no sorry wasn't what I was looking for exactly.

[cgnieder]

Hi,

I don't understand, why you want to keep the \underset command and the tabular environment?

Otherwise I would propose you use the possibilities which the chemmacros package offers, seeing that you are using it already.

Code: [Select all] [Expand/Collapse] [Download] (untitled.tex)

\documentclass[fleqn]{article}
\usepackage{amsmath}   
\usepackage[version=3]{mhchem}
\usepackage{chemmacros,siunitx}
 
\begin{document}
\newreaction*+{reactionsat}{alignat}
 
\begin{reactionsat*}{6}
  & 2 Na\solid{}   && {}  + 2 H2O\liquid{} && -> && 2 NaOH\aq{}    && {}  + H2\gas{} \\
  & 2 molecules    && \quad{} 2 molecules  &&    && 2 molecules    && \quad{} 1 molecule \\
  & \SI{2}{\mole}  && \quad \SI{2}{\mole}  &&    && \SI{2}{\mole}  && \quad \SI{1}{\mole} \\
  & \text{2(23)}   && \quad \text{2(18)}   &&    && \text{2(40)}   && \quad 2 \\
  & \SI{46}{\gram} && {}  + \SI{36}{\gram} && -> && \SI{80}{\gram} && {}  + \SI{2}{\gram}
\end{reactionsat*}
 
\end{document}

test.jpg (14.14 KiB) Viewed 5243 times

Regards

[ghostanime2001]

They are used because of the spacing between the chemical formulas the first line of text beneath it