Drawing and naming the alcohols
3 marks · Easy| Name | Molecular formula |
|---|---|
| methanol | CH4O |
| ethanol | C2H6O |
| propan-1-ol | C3H8O |
| butan-1-ol | C4H10O |
Name the alcohol with the molecular formula C3H8O.
What pattern do you notice in the number of hydrogen atoms as the number of carbon atoms increases by one?
Predict the molecular formula for the next alcohol in the series after butan-1-ol.
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.
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(a) propan-1-ol
(b) Increases by 2 hydrogens for each carbon added
(c) C5H12O
Common mistakes: Incorrect hydrogen pattern
Show mark scheme and worked solution
Marking points
B1 (a) · 1 mark · Correct name: propan-1-ol for C3H8O.
B1 (b) · 1 mark · States that the number of hydrogens increases by 2 for each extra carbon atom.
B1 (c) · 1 mark · Correct molecular formula: C5H12O.
Worked solution
a) C3H8O is propan-1-ol.
b) Each time the number of carbon atoms increases by one, the number of hydrogens increases by two.
c) Next in the series, after C4H10O, is C5H12O.