LaTeX forum ⇒ General ⇒ chemical equation numbering

[yotama9]

OK. the code I want if on page 11 and not 10. This is the source to my misunderstanding. This part start with explaining how to create a mhchem costume command in the equation environment so I skipped the end of this part. My mistake.

As for your code. I don't understand it completely. Is there a latex commands database to understand it? what does the @ or the $$ stand for?

Thanks.

[localghost]

OK. the code I want if on page 11 and not 10. This is the source to my misunderstanding. This part start with explaining how to create a mhchem costume command in the equation environment so I skipped the end of this part. My mistake. […]

References are mostly to the current version of a manual available on CTAN.

[…] As for your code. I don't understand it completely. Is there a latex commands database to understand it? what does the @ or the $$ stand for? […]

For the documentation of the LaTeX2e sources you can take a look at source2e (or a web search for source2e.pdf). The »at« sign protects important internal LaTeX commands and registers. It should be used very careful. The double dollar signs are a TeX command and enclose a displayed equation environment (not to be used in LaTeX syntax, see l2tabu).

Supplement:
In the meantime I was able to work out a more general solution that works with the standard classes. The relevant part of the code has to be modified as shown below.

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

\makeatletter
\@definecounter{reaction}
\def\reaction{$$\refstepcounter{reaction}}
\def\endreaction{\eqno \hbox{\@reacnum}$$\@ignoretrue}
\def\@reacnum{{\normalfont \normalcolor (\thereaction)}}
\@ifundefined{chapter}%
   {\renewcommand\thereaction{C\,\@arabic\c@reaction}}
   {\@addtoreset{reaction}{chapter}
    \renewcommand\thereaction{C\,\ifnum \c@chapter>\z@ \thechapter.\fi \@arabic\c@reaction}}
\makeatother

At the moment a starred version of the reaction environment is missing.

[rainsong]

Thanks @localghost! Your method solved my problem