4.5: Understand How to Write the Possible Structural and Displayed Formulae of an Organic Molecule Given its Molecular Formula

DISPLAYED FORMULA: Formula that graphically shows the number of atoms of each element in compound and the bonds that join them together (straight lines representing covalent bonds)

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Example: Ethene ( C2 H4 )

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From the molecular formula, we know that Ethene has 2 Carbon atoms and 4 Hydrogen atoms:

STRUCTURAL FORMULA: Formula that states the number of atoms of each element in compound and the bonds that join them together (straight lines representing covalent bonds)

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Example: Ethene

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Displayed formula of Ethene can be split up into sections and written as a formula:

Diagram showing the Conversion of Displayed Formula into a Structural Formula

OTHER EXAMPLES:

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MOLECULAR FORMULA	STRUCTURAL FORMULA	DISPLAYED FORMULA
METHANE CH4	CH4
PROPANE CH8	CH3 CH2 CH3
ETHENE C2H4	CH2 = CH2
ETHANOL C2H5OH	CH3 CH2 OH