Properties (Molecular Weight): Difference between revisions

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== Description ==
== Description ==


This article describes a method for providing the '''molecular weight''' of chemical compounds.
This article describes a method for retrieving the '''molecular weight''' of chemical compounds.


== Model theory ==
== Model theory ==


{{Under construction|section}}
{| style="float:right; margin-left: 10px;"; class="wikitable"
 
|+ Table 1. Atomic weight.{{KWA Kenwalt Australia Pty Ltd (2021)}}
:{| class="wikitable"
|+ Table 1. Atomic weight.
!Element || Atomic weight (g/mol)
!Element || Atomic weight (g/mol)
|-
|-
Line 217: Line 215:
| Zr || 91.224
| Zr || 91.224
|}
|}
This function returns the molecular weight of a chemical compound based on the atomic weights of its constituent elements.
The following applies to use of the molecular weight function:
* The atomic weights of the elements which are used by the function are presented in Table 1.{{KWA Kenwalt Australia Pty Ltd (2021)}}
* Only alphanumeric characters are allowed in the molecule definition
* Only stoichiometric (integer) counts of elements are permitted; no fractions or decimals
* Bracket notation is permitted
* Nested brackets are permitted
* Dot notation is not permitted; use brackets instead


== Excel ==
== Excel ==
Line 254: Line 262:
* the <math>^*</math> superscript denotes an optionally-returned result
* the <math>^*</math> superscript denotes an optionally-returned result
   |}  
   |}  
|  
|
:[[File:PropsMW1.png|frame|Figure 1. Example showing the selection of the input parameters (shaded blue frame), and Results (light blue frame) array in Excel. The parameter <math>\mathit{returnElementCount}=\text{True}</math> in this example.]]
:[[File:PropsMW1.png|frame|Figure 1. Example showing the selection of the input parameters (shaded blue frame), and Results (light blue frame) array in Excel. The parameter <math>\mathit{returnElementCount}=\text{True}</math> in this example.]]
|}
|}

Latest revision as of 13:15, 29 January 2024

Description

This article describes a method for retrieving the molecular weight of chemical compounds.

Model theory

Table 1. Atomic weight.[1]
Element Atomic weight (g/mol)
Ac 227
Ag 107.8682
Al 26.9815384
Am 243
Ar 39.948
As 74.921595
At 210
Au 196.96657
B 10.811
Ba 137.327
Be 9.0121831
Bi 208.9804
Bk 247
Br 79.904
C 12.0107
Ca 40.078
Cd 112.414
Ce 140.116
Cf 251
Cl 35.453
Cm 247
Co 58.933194
Cr 51.9961
Cs 132.90545196
Cu 63.546
Dy 162.5
Er 167.259
Es 252
Eu 151.964
F 18.998403163
Fe 55.845
Fm 257
Fr 223
Ga 69.723
Gd 157.25
Ge 72.63
H 1.00794
He 4.002602
Hf 178.486
Hg 200.592
Ho 164.930328
I 126.90447
In 114.818
Ir 192.217
K 39.0983
Kr 83.798
La 138.90547
Li 6.941
Lr 262
Lu 174.9668
Md 258
Mg 24.305
Mn 54.938043
Mo 95.95
N 14.0067
Na 22.98976928
Nb 92.90637
Nd 144.242
Ne 20.1797
Ni 58.6934
No 259
Np 237
O 15.9994
Os 190.23
P 30.973761998
Pa 231.03588
Pb 207.2
Pd 106.42
Pm 145
Po 209
Pr 140.90766
Pt 195.084
Pu 244
Ra 226
Rb 85.4678
Re 186.207
Rh 102.90549
Rn 222
Ru 101.07
S 32.065
Sb 121.76
Sc 44.955908
Se 78.971
Si 28.0855
Sm 150.36
Sn 118.71
Sr 87.62
Ta 180.94788
Tb 158.925354
Tc 98
Te 127.6
Th 232.0377
Ti 47.867
Tl 204.3833
Tm 168.934218
U 238.02891
V 50.9415
W 183.84
Xe 131.293
Y 88.90584
Yb 173.045
Zn 65.38
Zr 91.224

This function returns the molecular weight of a chemical compound based on the atomic weights of its constituent elements.

The following applies to use of the molecular weight function:

  • The atomic weights of the elements which are used by the function are presented in Table 1.[1]
  • Only alphanumeric characters are allowed in the molecule definition
  • Only stoichiometric (integer) counts of elements are permitted; no fractions or decimals
  • Bracket notation is permitted
  • Nested brackets are permitted
  • Dot notation is not permitted; use brackets instead

Excel

The molecular weight calculation may be invoked from the Excel formula bar with the following function call:

=mdProps_MW(Formula as String, Optional returnElementCount as Boolean = false)

Invoking the function with no arguments will print Help text associated with the model, including a link to this page.

The input parameters and calculation results are defined below in matrix notation, along with an example image showing the selection of the same cells and arrays in the Excel interface:

where:

  • is a string of characters representing the molecular formula of the substance
  • indicates whether to return a stoichiometric count of each element identified in the molecular formula (default is to omit)
  • is the molecular weight of the substance (g/mol)
  • is a string of characters representing the stoichiometric count of each element identified in the molecular formula
  • the superscript denotes an optionally-returned result
Figure 1. Example showing the selection of the input parameters (shaded blue frame), and Results (light blue frame) array in Excel. The parameter in this example.

References

  1. 1.0 1.1 KWA Kenwalt Australia Pty Ltd, 2021. SysCAD 9.3, software, Build 139.