The Formula Weight Calculator is a powerful tool for chemists, allowing quick and precise calculations for molecular mass, elemental composition, isotopes, and ionic species. Its speed buttons and argument-based inputs make it highly efficient for both educational and professional use.The Molecular Calculator is designed to be user-friendly, especially for tablet users, with speed buttons and versatile calculation options. It provides essential chemical data for various molecular and ionic compounds.
27 Common Elements: Quickly insert frequently used chemical elements.
11 Common Functional Groups: Includes SO4, CrO7, NO3, CH3COO, and others for rapid formula entry.
Formula Mass Calculation: Computes the molecular weight of a given formula.
Amount in Moles: Displays the molar quantity of a compound.
Mass & Moles (Argumented Input): If specified, the calculation provides both molar and mass values.
Element Breakdown:
Number of atoms (element-wise)
Molar amount of each element
Mass contribution of each element
Mass percentage of each element
Isotope Support: Calculates formula weights for enriched compounds using all stable isotopes (H to Lr). Isotopes are denoted using square brackets, e.g., C[13], H[2] (deuterium), or heavy water H[2]2O.
Custom Argumented Formulas:
Mass-based input: 2gH2O (2 grams of
H2O) or 2gO,H2O (2
grams of oxygen in H2O).
Mole-based input: 2mH2O (2 moles of
H2O) or 2mO,H2O (2
moles of oxygen in H2O).
Hydrated Compounds:
Supports calculations for crystal water compounds, e.g
CaCl2*2H2O
Coordination Complexes:
Allows input for structures such as [Fe(CN)6]+2
Ion Calculations:
Accepts ionic notations, e.g. SO4-2 or Ca+2 (or
SO4-- or Ca++)
Adjusts mass calculations based on electron loss or gain in ionic species.
Input a Molecular Formula: Type or use speed buttons to enter a chemical formula.
Specify Calculation Mode (argumented formula):
Enter arguments (g for mass, m for moles) if
required e.g. 2mH2SO4 (2 moles of H2SO4)
Use brackets for isotopes e.g. H[2] (Deuterium)
Include water of crystallization where necessary
e.g. CaCl2*2H2O
View Results: The calculator displays the computed formula weight, molar and mass amounts, and element-wise breakdown.
Notation &
Conventions
Examples
Interpretation
------------------------------------------------------------------------------------------------------------------
m
| 2mH2O |
mol
g
| 2gH2O
| gram
E
| 2E-3mH2O | exponent
e
| 2e-3mH2O | exponent
e-
| e-
| electron symbol
(typical used in Redox)
-
| CH3-CH2-CH2 | Condensed (semi-structural) formula
-
| SO4-2
| neg. charged ion (Note:Must not be written as
SO42-)
|
SO4-- | neg. charged ion
+
|
Ca+2 | pos. charged ion
(Note:Must not be written as Ca2+ )
|
Ca++ | pos. charged ion
.
|
2.3gH2O | decimal separator
,
| 2mH2,H2O |
argument separator
*
| CaCl*5H2O | crystal water separator
D
|
D2O | deuterium (special
option this isotope)
H[2]
| H[2]2O
| X[nucleons] e.g. C[13] normal isotope notation
[]
| H[2]
| number of nucleons enclosed in
square brackets
| [Fe(CN)6]+2 | Coordination
complexes
()
| Ca(NO3)2 | braces
0-9
|
10gH2 | numbers
H-Lr
| HHeLiBeBC | Elements: Hydrogen ...
Carbon
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Example - Complex enriched by isotopes: [Fe[54](C[13]N[14])6]+2
Example - Condensed (semi-structural) negative ion:
CH3-CH2-CH2-CH2O-
Note: Charged atoms/molecules using CHEMIX School Molecular
Calculator
Legal :
Ca++
SO4--
Legal :
Ca+2
SO4-2
Illegal:
Ca2+
SO42-
Ensure correct notation for ions and isotopes to get accurate calculations.
The tool automatically corrects formula mass for ions based on electron changes.
It supports complex structures like hydrated compounds and coordination complexes.