Drawing and naming the alcohols
2 marks · EasyExplain why butan-1-ol and propan-1-ol are both classified as alcohols, even though they have a different number of carbon atoms.
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Must show: Both contain the –OH (hydroxyl) functional group, Alcohols are defined by the presence of –OH group, regardless of carbon chain length
Common mistakes: Confusing with alkanes because of 'an' in name
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Marking points
B1 · 1 mark · States that both butan-1-ol and propan-1-ol contain an –OH (hydroxyl) functional group.
B1 · 1 mark · Recognises that all alcohols are defined by having an –OH group, no matter how many carbon atoms are present.
Worked solution
Alcohols are a homologous series of organic compounds that all contain the –OH (hydroxyl) functional group. Both butan-1-ol and propan-1-ol have this group, even though butan-1-ol has four carbon atoms and propan-1-ol has three. The number of carbons does not affect the functional group or classification as an alcohol.