11 1 formulae functional groups and terminology

A displayed formula shows the spatial arrangement of all the atoms and bonds in a molecule.

Structural formulae show enough information to make the structure clear, but most of the actual covalent bonds are omitted. Only important bonds like double and triple bonds are always shown.

A molecular formula is the actual number of atoms of each element in a compound.

Structural isomers are compounds that have the same molecular formula but different structural formulae.

False. In structural formulae, only important bonds like double and triple bonds are always shown.

True. In displayed formulae, all covalent bonds are always shown.

The displayed formula of propane is:

The structural formula of propene is CH3CH=CH2.

The displayed formula of ethene is:

False. The displayed formula for ethanol is:

True. CH3CH2CH=CH2 and CH3CH=CHCH3 are structural isomers of one another.

True. CH3CH(OH)CH3 is an isomer of CH3CH2CH2OH as the OH group has moved from the middle carbon atom to the end carbon atom. The molecular formula is the same.

A homologous series is a series or family of organic compounds that have similar features and chemical properties due to having the same functional group.

The general formula shows a ratio of atoms in a family of compounds in terms of 'n' where n is a varying whole number.

True. A functional group is a group of atoms bonded in a specific arrangement that influences the properties of the homologous series

All members of a homologous series have:

The functional group of an alcohol is R-OH

False. The alkene functional group is represented by C=C.

The general formula for alkanes is CnH2n+2.

The general formula for alkenes is CnH2n.

True. All members of a homologous series have the same general formula.

The general formula of alcohols is CnH2n+1OH.

The general formula of the carboxylic acids is CnH2n+1COOH.

Saturated compounds are molecules in which all carbon-carbon bonds are single bonds.

Unsaturated compounds are molecules in which one or more carbon-carbon bonds are not single bonds. They contain carbon-carbon double bonds (C=C).

False. Alkanes are examples of saturated compounds.

Alkenes are considered unsaturated because they contain one carbon-carbon double bond.

The double bond in alkenes can open up, allowing incoming atoms to form another single bond with each carbon atom of the functional group.

Saturated compounds contain only single covalent bonds between carbon atoms.

The following compound is saturated.

The following compound is unsaturated.

The prefix tells you the number of carbon atoms in the longest continuous chain in the compound.

There are three carbon atoms in the carbon chain if the prefix is prop-.

The suffix tells you what functional group is on the compound.

The name of CH3CH2CH2CH2OH is butan(-1-)ol.

The name of CH3CH2CH2CH2CH3 is pentane.

The name of CH3CH2COOH is propanoic acid.

The name of CH3(CH2)3HC=CH2 is hex(-1-)ene.

False. The name of CH3COOCH2CH3 is ethyl ethanoate. The two carbon atoms highlighted (in bold) come from the carboxylic acid used to form the ester.

False. Numbering in organic compound names sometimes starts from the right to keep the numbers as low as possible.

The name of the following alcohol is butan-2-ol.