Drawing and naming the alcohols

3 marks · Normal

An alcohol contains four carbon atoms in a straight chain with the –OH group attached to the second carbon.

State the IUPAC name of this alcohol. Show all steps in your answer.

Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.

Show answer

butan-2-ol

Also accept: 2-butanol; butanol-2

Common mistakes: butan-1-ol; butan-4-ol

Show mark scheme and worked solution

Marking points

M1 · 1 mark · Identifies the base name for a four-carbon alcohol as 'butan'.

M2 · 1 mark · Correctly identifies that the –OH group is on the second carbon (position 2).

A1 · 1 mark · Writes the correct IUPAC name: 'butan-2-ol'. Accept '2-butanol' or 'butanol-2'. (follow-through)

Worked solution

Step 1: The alcohol has four carbon atoms, so the base name is "butan".

Step 2: The –OH group is attached to the second carbon atom.

Step 3: According to IUPAC rules, the position of the –OH is indicated by a number. The correct IUPAC name is butan-2-ol.