Chemeq - Chemical Equation Analyzer

chemeq [options]

Chemeq is a chemical equation analyzer. It is a fast lexical and syntaxic analyser which helps to find out chemical informations embedded in source chemical equations. Data can be output in various sophisticated formats, depending on options. 'chemeq' defaults to 'chemeq -mlcwn'.

Options are active only if chemeq parses an equation of chemical reaction. If chemeq parses the formula of a simple chemical, no option is taken in account, the output is just a straightforward TeX string representing the simple chemical.

-h Displays Help.

-M

Outputs al list of space separated molecular weights.

-m Outputs a Minimal output. It allows chemeq to be idempotent, i.e. the command 'chemeq | chemeq' is equivalent to 'chemeq'.

-l Outputs a LaTeX string representing the chemical equation.

-c Outputs a message giving informations about the Conservation of elements and charges in the equation. 'OK' means that both elements and electric charges are balanced.

-w Outputs the LaTeX string representing the Gulder-Waage equation related to the input chemical equation, or the Nernst equation, if the input equation is a redox semi-equation.

-n Outputs a Normalized string accounting for the input equation. Two chemical equations having the same normalized string are chemically equivalent, even if the molecules are scrambled around and the coefficient are not equal but proportionnal.

echo "1/2 Cu^2+ + OH- -> 1/2Cu(OH)2s" | chemeq

will display informations about the reaction of hydroxyde and Cu II ions.

echo "MnO4^- + 8H3O^+ + 5e- --> Mn^2+ + 12 H2O" | chemeq

will display informations about the reaction of reduction of permanganate ions in an acid environment.

echo "MnO4^- + 8H3O^+ + 5e- --> Mn^2+ + 12 H2O" | chemeq -w

will display the LaTeX format for the Nernst law related to the reduction of permanganate ions in an acid environment.

echo "MnO4^- + 8H3O^+ + 5e- --> Mn^2+ + 8 H2O" | chemeq -c

will highlight the lack of conservation of elements H and O (water molecules are not well balanced).

allthough in some cases, shorter expressions are sucessfully parsed, it is safer to consider that an "up arrow" (^) must be put before the charge symbols of an ion. Examples : H3O^+, Fe(CN)6^4-, OH^-

Georges Khaznadar, 
  <georgesk@boltz.univ-littoral.fr>

When not specified, chemical entities coming from the standard input are believed to be in aqueous solutions. Water is considered by default as the main solvent. Only one liquid (aqueous) phase is currently taken in account. All solid chemical entities are considered as parts of separated phases. Suffixes _s, _g and _aq can be used to enforce the type of some chemical entities.