AllChemicals — The Online Chemical Glossary | https://allchemicals.info/chemical/584-molecular-formula
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Quick Reference
Also Known As
True formula, molecular composition formula, empirical formula (related but different)
What is Molecular Formula?
A chemical formula showing the actual number of atoms of each element in one molecule of a compound, without indicating structure. For example, glucose is C₆H₁₂O₆. The molecular formula can be derived from the empirical formula and the molar mass of the compound.
Properties & Characteristics
The molecular formula gives the actual number of atoms of each element present in one molecule of a compound. It is a whole-number multiple of the empirical formula: molecular formula = n × empirical formula, where n = molar mass / empirical formula mass. For example, glucose: empirical formula CH₂O (EFM = 30), molecular formula C₆H₁₂O₆ (MM = 180, n = 6). The molecular formula gives complete elemental composition but does not indicate how atoms are connected (structural formula does).
Uses & Applications
Molecular formulas are used in: writing balanced chemical equations, calculating molar mass, identifying compounds by high-resolution mass spectrometry (exact mass), and as a starting point for structural elucidation. IUPAC systematic nomenclature is derived from the molecular formula connectivity.
Safety Information
Molecular formula alone does not reveal hazard — ethanol (C₂H₆O) and dimethyl ether (C₂H₆O) are structural isomers with the same molecular formula but very different properties. Always identify the specific structure, not just the formula, before making safety assessments.
Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.
SynonymsTrue formula, molecular composition formula, empirical formula (related but different)
Frequently Asked Questions
A chemical formula showing the actual number of atoms of each element in one molecule of a compound, without indicating structure. For example, glucose is C₆H₁₂O₆. The molecular formula can be derived from the empirical formula and the molar mass of the compound.
Molecular formulas are used in: writing balanced chemical equations, calculating molar mass, identifying compounds by high-resolution mass spectrometry (exact mass), and as a starting point for structural elucidation. IUPAC systematic nomenclature is derived from the molecular formula connectivity.
Molecular formula alone does not reveal hazard — ethanol (C₂H₆O) and dimethyl ether (C₂H₆O) are structural isomers with the same molecular formula but very different properties. Always identify the specific structure, not just the formula, before making safety assessments.
Editorial standards: Chemical data is sourced from peer-reviewed literature,
CAS Registry, NIST WebBook, and PubChem. Safety information reflects guidance from OSHA, ECHA,
and IAEA. For educational purposes only — always consult official SDS documentation and qualified
professionals before handling chemicals.
