A quick introductory look at the alcohols
4 marks · NormalThis question is about the naming of alcohols.
State the suffix used in the names of alcohols.
The following compounds are alcohols:
| Compound | Structural Formula |
|---|---|
| Methanol | CH3OH |
| Propanol | C3H7OH |
Explain why the names of these compounds end with this suffix.
Describe how the position of the functional group can be shown in the names of alcohols containing more than two carbon atoms.
What would be the name of an alcohol with the structural formula CH3CH2CH2OH?
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(a) -ol
(b(i)) Because both compounds contain the -OH functional group (alcohol group) attached to a hydrocarbon chain.
(b(ii)) By using a number before the '-ol' to show which carbon the -OH group is attached to (e.g. propan-1-ol).
(c) propan-1-ol · must show must state propan-1-ol or '1-propanol'
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Marking points
B1 (a) · 1 mark · States the correct suffix for alcohols: '-ol'
B2 (b(i)) · 1 mark · Correctly explains that the suffix is used because the compound contains the -OH functional group (alcohol group).
B3 (b(ii)) · 1 mark · States that the position is shown by a number before '-ol', indicating carbon attached (e.g. propan-1-ol).
B4 (c) · 1 mark · Gives the correct name: propan-1-ol (accept 1-propanol).
Worked solution
a) The suffix used is -ol.
b) i) The names of these compounds end with '-ol' because they contain the -OH functional group (an alcohol group).
b) ii) The position of the functional group is shown by numbering the carbon atom to which the -OH group is attached, written before the '-ol' ending, e.g. propan-1-ol.
c) The compound CH3CH2CH2OH is called propan-1-ol (or 1-propanol).