Empirical formula

In chemistry, the empirical formula of a chemical is a simple expression of the relative number of each type of atom (called a chemical element) in it. An empirical formula makes no reference to isomerism, structure, or absolute number of atoms. Empirical formulas are the standard for ionic compounds, such as CaCl2, and for macromolecules, such as SiO2. The term empirical refers to the process of elemental analysis, a technique of analytical chemistry used to determine the relative percent composition of a pure chemical substance by element.

Related Topics:
Chemistry - Atom - Chemical element - Isomer - Elemental analysis - Analytical chemistry

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In contrast, the molecular formula identifies the absolute number of atoms of such element to be found in each discrete molecule of that compound.

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For example, hexane could have a structural molecular formula of CH3CH2CH2CH2CH2CH3, implying that it has a straight chain structure, 6 carbon atoms, and 14 hydrogen atoms. The hexane molecular formula is C6H14. And the empirical formula for the same molecule would be C3H7 showing a C:H ratio of 3:7.

Related Topics:
Hexane - Molecular formula - Carbon - Hydrogen

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