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Author: Subject: Molecular weight calculator.
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[*] posted on 14-11-2005 at 00:53
Molecular weight calculator.

Having lurked around here for some time I thought I could give something back.

This is a excel sheet that contains macros to calculate molar mass.

For the suspicious amongst us, I have left the macros unprotected. This enables you to load the sheet without macros enabled and look at the code to check it's not malicious.

There are 2 useable macros GetElement() and GetMolarWeight(). To use them, look at the examples on the sheet.


Attachment: MoleWeight.xls (41kB)
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[*] posted on 30-11-2005 at 05:01

Just curious, does nobody find this useful?

Is it because it's an excel spreadsheet?
Is this something readily available elsewhere?
Would it be more useful if it was a stand alone program?

As I said, just curious as I thought this would be something that people would find useful.

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[*] posted on 30-11-2005 at 06:08

Yes, such a thing is quite useful. I have written my own program some time ago for doing this (and much more). The program balances equations, but it can also be used for simply computing molar masses. It is a standalone Windows program and requires no setup at all.

For simply computing molar masses type the molecular formula in the left column and in the right column. I intend to modify the program such, that it also allows simple MW-computations, if the right column is left empty.

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[*] posted on 30-11-2005 at 14:47

Yet another

chemical equation balancing

program - does it all. Molar mass calculation, equation balancing, stoichiometry, limiting reaagents, plus n=CV and pV=nRT calculators to facilitate calculations including solutions and gases.

[Edited on 4-12-2005 by Borek]

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[*] posted on 1-12-2005 at 13:48
Simple application for calculating mol mass

Hi, Here is a small application written in Delphi for calculating molecular masses. Dont worry, no spywares/viruses...

Have fun and distribute freely

Attachment: MolMass.rar (93kB)
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[*] posted on 4-8-2006 at 08:16

Another one for molar mass calculations.

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[*] posted on 4-8-2006 at 17:57

LCS is a chemistry and data analysis program. LCS isn't a chemistry education program. It's a program for your daily laboratory work. LCS supports an enormous range of chemical, numerical und statistical functions. I believe, you´ve never seen such a comprehensive chemistry program as FREEWARE.

LCS is a Windows 3.1 program, but it works under Windows95/98 and Windows NT, too. You can use LCS on PowerMacs with the Virtual PC 3.0 emulator. LINUX users can use the WINE windows emulator for LCS.

This is a short overview about the basics of LCS. Additional,
LCS includes a huge english ONLINE-help for every subject of LCS.

Hardware requirement:

- min. 486DX33 / 8MB RAM / 640*480 16 colors or higher
(386/40 4MB is possible, too)

Graphic resolution: 1024*768/256 colors will be great

- min. 3 MB free harddisc space

Copyright : see file COPYRGHT.TXT


Copy LCS_E121.ZIP from my website.

The program LABORANT.EXE will start LCS. Decompress the the ZIP file in your destination directory. Start Laborant.,exe in the folder LCS_ENGL.
LCS is a very stable program. If your LCS is unstable, please read the file BUGS.TXT for BWCC.DLL/BC450RTL.DLL bug fixing.


This is an index of all functions of LCS. LCS has an enormous range of chemical, numerical and statistical functions. It´s a very fast and compact windows application. The program algorithms of LCS are optimized for speed and size.

1. Stoichiometry, formulas and equations

- Molmass determination of formula
- Quantities in formulas
- Quantities in equations
- Build a chemical equation
- Titration
- Empiric formula
- Kjeldahl analysis
- Formula macro handling
- Formula buffering
- Load/save equations

2. Chemical solutions and conversions

- Chemical mixture solver (great tool !)
- Convert units
- Convert mol in quantity
- Convert quantity in mol
- Convert mass constituent in molarity
- Convert molarity in mass constituent
- Determine molarity
- Determine molality
- Solution of crystalline water substances
- Mixture rules / cross
- Solution of titrimetric standard substances

3. Thermochemistry

- Thermochemistry database handling
- THC database import and export
- Analysis of thermochemical reactions
- Analyze only educt sides of THC-reaction
- Reaction enthalpy:
- dH = -R(lnK1-lnK1)/(1/T1-1/T2)
- dH = dG + TdS
- Entropy change:
- dS = (dH-dG)/T
- dS = nR*ln(P1/P2)
- Free energy change:
- dG = -RT*lnK
- dG = dH - TdS
- dG = nF*E0
- Equilibrium constant K:
- K aus MWG berechnen
- K = exp(-dG/RT)
- K = exp((E0*nF)/RT)
- K2 = exp(dH/R*((T2-T1)/(T1*T2))+lnK1)
- Ulich approximation for K
- Calculate Cp(T) with temperature polynomial
- Transform Cp(T) polynomials
- Chemical equilibria (iterative)
- Electromotive force (EMF) :
- EMF =-dG/nF
- EMF = RT*lnK/nF
- Nernst equation:
- E = E0 - RTlnQ/nF
- E0 = E + RTlnQ/nF
- Determine molmass with osmotic pressure
- Determine molmass with vapor pressure depression
- Clausius-Clapeyron equation:
- Vapor enthalpy (from T,p datas)
- Vapor pressure p2
- Temperature T2
- Enthalpy of gaseous ions from organic molecules
- Enthalpy table of gaseous ions
- Add bond energies of organic molecules
- Van der Waals equation:
- Molar volume (Newton)
- a,b for critical point
- 2nd virial coefficient B
- Freezing-point depression:
- Beckmann method
- Rast method

3. pH calculations

- pH of strong acid
- pH of strong base
- pH of 1-protonic acid
- pH of 2-protonic acid
- pH of 1-base
- pH of 2-base
- pH of 1-protonic acid (iterative)
- pH of n-protonic acid (iterative)
- pH of salt solution type HA/B
- pH of n-protonic acid and 1-base
- Titration curves of HA, H2A, H3A with MOH
- Titration degree tau from pH of n-protonic acid with m-base
- pH from titration degree tau of n-protonic acid with m-base
- Linear pH diagram (file)
- Logarithmic pH diagram (file)
- pH of buffer HA/A- + HX
- Buffer capacity ß of HA/A-
- Buffer capacity ßmax
- Ionic strength
- Solubility Cs
- Solubility product
- Protonation constant a of n-protonic acids
- Table of pKa values
- Table of pKb values
- Ampholyte info

4. Reaction kinetics

- Reaction order / rate constant (method 1)
- Reaction order / rate constant (method 2)
- Reaction order (method 3)
- Activation energy (Arrhenius)
- Rate constant (Arrhenius)
- Consecutive reaction 1st order A->B->C
- Reversible reaction 1st order A <=> B
- Parallel reaction 1st order A->B A->C
- Solution of elementary reactions with
differential equation systems (DEQ)

5. Electrochemistry

- Activation coefficient (Debye-Hückel)
- Standard potentials (table)
- Quantity from electrochemical reaction

7. Biochemistry

- Polypeptide sequencer (element proportion)
- DNA/RNA sequencer (element proportion)
- Table of nucleotides
- Table of amino acids
- Load/save biochemical sequences
- Input rules for biochemical sequences

8. Optical methods

- Convert extinction <-> transmission
- Lambert-Beer law:
- c = E/ed
- m = E*V*M/(e*d)
- Molar rotation
- Molar extinction coefficient
- e = E/cd
- e = E*M*V/(m*d)

9. Gas laws

- Boyle-Mariotte law
- Gay-Lussac law
- Ideal gas law
- Molmass determination of gases
- Convert molvolume in liter
- Convert liter in molvolume

10. Miscellaneous

- Distribution equilibria (Nernst)
- Quantity n after x extractions
- Calculate number of extractions
- Calculate viscosity

11. Periodic system of elements

- Integrated PSE
- Element information
- Group information
- Cation information
- Anion information

12. Tables

- Important physical constants
- Cryoscopic constants
- Important spectra lines
- Density of inorganic solvents
- Density of organic solvents

13. Exercise programs

- Formula exerciser (great !)
- Formula identifier

14. Function parser

- Function parser for functions of type f(x) and f(x,y)
- Function manager
- Function calculation

15. Differential equations (DEQ)

- Runge-Kutta method 4th order
- Runge-Kutta-Fehlberg method
- Solve stiff DEQ

16. Numerical mathematics

- Linear regeression
- Polynomial approximation 2nd - 5th degree
- Approximation of function type:
- A(x) = a * e^(bx)
- A(x) = a * x^b
- A(x) = a + b*ln(x)
- A(x) = a + b*1/x
- Numeric integration (Simpson)
- Numeric differentation of data set
- Fourier approximation (real)
- Romberg integration
- Integration with cubic splines
- Finding of roots (Newton-Raphson)

17. Statistics

- Q-test (outlying test n<=10)
- Outlying test(n>10)
- F-test
- t-test (Student test)
- Bartlett test
- Gamma function
- Simple analysis of variance
- Coefficient of correlation
- Limit of detection
- Normal distribution (probability P)

18. Data input window

- Load/save experimental data
- Import/export of datas
- Edit, sort and transform data

19. Error determination

- Arithmetic mean
- Median
- Range
- Standard deviation
- Variance
- Coefficient of variation
- Mean error of mean value

20. Data import/export

- Data export:
- Standard format of LCS .MSW
- ASCII Delimited .DEL
- DIF format .DIF
- Microsoft Symbolic Link Format .SLK
- ASCII text
- HMTL table
- Data import
- CSV format
- EXCEL ASCII format
- dBase III DBF format

21. Linear equation systems / matrices

- Load/save LES / matrix
- Edit LES/matrix
- Transponate matrix
- Solve linear equation system
- Calculate determinant
- Invers matrix
- Householder transformation
- Determine eigenvalues
- Matrix condition (Hadamard)
- Add matrices
- Multiply matrices

22. Data plotter window

- Plot data and regression curves
- Plot mathematical functions f(x), f'(x)
and integral of f(x)
- Scale graph and set grid
- Set title and axis text
- Zoom graph
- Save graph as BMP picture
- Save graph into clipboard

23. TeX-/RTF support

- TeX formula generation
- TeX equation generation
- TeX data table generation
- TeX LES generation
- TeX LES solution generation
- TeX matrix generation
- TeX determinant generation
- Save formula/equation in RTF format

In addition to the listed operating systems, Laborant works with Win2K as well :) It can be downloaded in English or German from:


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