                                  OneOhOne

This free program does many of the calculations found in the first semester
of a chemistry course (such as chem 101, hence the name).  The main features
are:

        Formulas can be rearranged with the mouse or menu.  For 
         example, moles = g / (molar mass) can be rearranged to 
         molar mass = g / moles.
      
        Formulas in different modules can be connected.  For example, 
         moles calculated in the g <--> mole module can be connected to 
         the molarity module.  A change in grams in the g <--> mole module
         changes the moles input to the molarity module, which changes the 
         calculated molarity.

        Uncertainties can be entered and are displayed.  These are
         calculated from a "propagation of errors" analysis.

Version 1.1 fixes a bug that sometimes prevented the percent module from 
making a connection.

OTHER FILES
-----------
101.ICO is an icon for Windows.  To add MolarMas to Windows, 
     Drag 101.exe from file manager onto program manager.
        It is given a default icon.  
     To change the icon, from program manager select File, Properties..., 
        Change Icon..., OK, Browse, and select 101.ICO from the 
        appropriate directory.
        
SOURCE.ZIP contains the source code, written using visual basic for
DOS.  Unless you are interested in the code and have VB, you might as well 
delete the file.  Unzip that file in its own directory.

UNCERTIN.XLS is a worksheet (saved in Lotus 1-2-3 format so older 
programs can read it) that calculates the uncertainty in elemental mass 
from uncertainty in isotopic abundances and masses.  The worksheet contains
data for the isotopes found in all the nonradioactive elements.  It can be
used to calculate the uncertainty in an isotopically enriched sample of an
element.

ELEMENTAL MOLAR MASS
____________________
This term, which has units of g/mol, is used in place of atomic weight,
which has units amu.

DISTINGUISHED FLUORINE
----------------------
So you enter F2 and get these results:
    Symbol  Number  % Composition   Atomic Weight
    ______  ______  _____________   _____________
      F     2          100           18.9984032(9)

                     Molar Mass:     37.996806(2)

Fine, no problem.

Now you enter F1F1 and get these results:
    Symbol  Number  % Composition   Atomic Weight
    ______  ______  _____________   _____________
      F     1        50.000000(3)    18.9984032(9)
      F     1        50.000000(3)    18.9984032(9)

                     Molar Mass:     37.996806(1)

How come the uncertainty in the molar mass is .000001 for F1F1,
and .000002 for F2?  The reason is that the fluorine atoms in
F1F1 are distinguishable, and indistinguishable in F2.  That is,
you can tell one F from the other in F1F1.  The bottom line is
that the uncertainty in the molar mass is less if you introduce
the fiction that you can tell one F from another.  Or one carbon
from another.  As when you enter toluene as Ph1Me1 instead of
C7H8.  In short, any time abbreviations are combined that contain
the same atoms, such as Ala2Gly1, the calculated uncertainties
will be low.  

Sometimes atoms are distinguishable.  For example, to determine 
just the C bonded to O in CH3CO2H, you might decompose the 
compound and collecting CO2.  To get the uncertainty in percent 
C as CO2 in the compound, enter the formula as C1C1H4O2 instead 
of C2H4O2.


THE MATH
--------
The calculation of uncertainty is the subject of a paper that will
be submitted to the Journal of Chemical Education.


REFERENCES
----------
Atomic weights are from "Atomic Weights of the Elements 1993", Pure &
Appl. Chem., 1994, 66(12), pp. 2423-2444.



Holler if you find a bug, or have a suggestion.  

     Christopher King
     Associated Western Universities
     723 The Parkway
     Richland, WA 99352
     Chris.King@pnl.gov
