4.2: Understand How to Represent Organic Molecules using Empirical Formulae, Molecular Formulae, General Formulae, Structural Formulae and Displayed Formulae

DEFINITIONS:

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TERM	DEFINITION
EMPIRICAL FORMULAE	Ratio of atoms of each element in compound in simplest form (whole number)
MOLECULAR FORMULAE	Chemical formula showing the elements and number of atoms of each element in compound
GENERAL FORMULAE	Formula that states the ratio of atoms of each element in formula of every compound in specific homologous series
STRUCTURAL FORMULAE	Formula that states the number of atoms of each element in compound and the bonds that join them together (straight lines representing covalent bonds)
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 (C2H4)

DESCRIPTION	FORMULA
EMPIRICAL FORMULAE	CH2
MOLECULAR FORMULAE	C2H4
GENERAL FORMULAE	CnH2n
STRUCTURAL FORMULAE	CH2 = CH2
DISPLAYED FORMULA