Typesetting chemical reaction equations

[Ville Voipio <ville.voipio@kpatents.com>]

I would need to typeset some rather simple reaction equations. I do not 
need the structural capabilities of PPCHTeX, just something simpler. The 
thing I am writing has something to do with physical chemistry, so I 
need mathematical equations, as well.

Of course, the natural way to do this:

\placeformula
\startformula
   \rm
   NH_3(g) + H^+(aq.) + Cl^-(aq.) \rightarrow NH_4^+(aq.) + Cl^-(aq.)
\stopformula

This gives rather pleasant-looking results. However, is this the right 
(i.e. kosher) way of doing things, or do I run into trouble at some 
later point with this? What are you chemists using?

And how do I switch off the equation numbering for the chemical 
reactions (I'd like to have the mathematical formulae still numbered)?

TIA,

- Ville