Provided by: chemeq_2.9-1_amd64 bug

NAME

       Chemeq - Chemical Equation Analyzer

SYNOPSIS

       chemeq [options]

DESCRIPTION

       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 -mlcwCn'.

OPTIONS

       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.

       -v     Displays the Version number

       -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.

       -C     Outputs  a  detailed   Count of the molecules and atoms contained in each member of
              the chemical equation. For example for the equation "H2_g + 1/2 O2_g  -->  H2O"  it
              outputs: "H2_g|H:1*2, 1/2 O2_g|O:1/2*2; H2O|H:1*2 O:1*1"

       -e     Outputs a detailed count of the Electrical charges.

       -s     Outputs a list of the chemical Species.

       -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.

ENVIRONMENT VARIABLES

       chemeq_input
              if  set,  this variables's value overrides the standard  input. If this variable is
              not set, the variable w_chemeq_input is taken  in  account  (useful  for  the  WIMS
              server).

       chemeq_option
              if  set,  this  variable's value overrides the options.If this variable is not set,
              the variable w_chemeq_option is taken in account (useful for the WIMS server).

EXAMPLES

       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).

NOTE: syntax of ions

       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^-

Composing chemical equations.

       Two  operators  are  defined,  #  as  an  additive oprator and ~ (tilde) as a substractive
       operator: they allow to compose several chemical equations

       echo "MnO4^- + 8H3O^+ + 5e- --> Mn^2+ + 8 H2O ~ 5Fe^3+ + 5e- -> 5Fe^2+" | chemeq
              will display the pure redox equation from the first equation, minus the second one.
              Electrons are simplified. So it will be equivalent to:

       echo "MnO4^- + 8H3O^+ + 5Fe^2+--> Mn^2+ + 8 H2O + 5Fe^3+" | chemeq
              which is their combination.

Mutiplying a chemical equation by one coefficient.

       The  operator  *  permits  to  multiply a whole equation by one coefficient which may be a
       fraction. Here is an example:

       echo "5 * Fe^3+ + e- -> Fe^2+" | chemeq
              will be equivalent to

       echo "5Fe^3+ + 5e- -> 5Fe^2+" | chemeq

Combining chemical equations, with coefficients.

       The two previous techniques can be used at the same time, which enables you to  make  more
       comlicated combinations, like this one:

       echo  "Fe^3+  +  e^-  -> Fe^2+ (0.77 V) # Fe^2+ + 6CN^- -> Fe(CN)6^4- (Kfa=1e24) ~ Fe^3+ +
       6CN^- -> Fe(CN)6^3- (Kfb=1e31)" | chemeq
              which will work as expected, and yeld a good value for the  standard  potential  of
              the redox couple of hexacyanoferrate II and III ions.

AUTHORS

       Georges Khaznadar,
         <georgesk@ofset.org>

KNOWN BUGS

       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.

       There  may  be  problemes  when  you  write  a standard potential with no decimal dot. For
       example, the entry Mn^2+ + 2e^- -> Mn_s (-1 V) would trigger an error. Then write Mn^2+  +
       2e^-  -> Mn_s (-1.0 V) or the more accurate value Mn^2+ + 2e^- -> Mn_s (-1.18 V) and there
       will be no error.

                                           4 june 2000                                  chemeq(1)