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Mass calculator Dalton Home
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Learning
Edition |
Professional
Edition | Handbook
These programs, for calculation of molar or formula
masses, were developed because none among a lot of freeware or shareware
programs of the same kind fits the qualifications listed below.
There are two editions of McDalton.
Handbook
About these programs In these programs there are not drawn up any special rules for typing chemical formulas. Just type them as you normally do. Nothing extra to learn and remember. This is made clear by examples in the McDalton Learning Edition program window shown on this page. The McDalton Professional Edition is the only program, or maybe one of a few programs of this kind, that is able to calculate molar mass of a substance like sodiumiron(III)sulfate, 3Na2SO4·Fe2(SO4)3·6H2O. A propagation of error analysis of the result is always made and the mass is then rounded to a plausible number of significant figures. In the Professional Edition the absolute maximum error of the result is displayed. In this edition the calculations is shown if the mouse is paused over the values. In the Learning Edition rounded masses are displayed if "Best round off result" is selected from the menu. According to international conventions and for learning purposes chemical formulas are formatted like CuSO4·5H2O and not like CuSO4*5H2O as in many other applications. In the Learning Edition leading numbers like 2Na are not allowed. This is because students often tend to include coefficients from chemical reaction formulas in their calculations. This may lead to difficulties in their studies later on. There is no limitations of this kind in the Professional Edition because a few chemical formulas actually begin with a number. For security and learning purposes elements must be entered in proper capitalisation. For example Co means Cobalt while CO means Carbon and Oxygen. These programs are named after John Dalton, the founder of modern atomic theory. He was born on September 6, 1766 in Eaglesfield, England. The atomic theory was based on works on mass and chemistry done by Dalton, Proust and Lavoisier.
You will find information and more applications by the same author at Chemistry
for Free, chem4free.info
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This
is a freeware computer program, designed for
learning purposes, to calculate molar or formula
masses. For this reason the calculations are shown together with the result.
An
example will make this clear. The molar mass for PbO is calculated as 207.2
+ 15.9994 = 223.1994 and the uncertainty in the molar mass
is calculated as 0.1 + 0.0003 = 0.1003. The only significant figure in
the uncertainty is the first decimal and therefore molar mass is given
as 223.2 ± 0.2 which is the best value and of course the uncertainty
is rounded up as explained before.