Unsaturated hydrocarbons
2 marks · NormalState the general formula for alkenes. Draw the displayed formula of propene.
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Also accept: The general formula for alkenes is CnH2n. Displayed formula for propene: H2C=CH-CH3 or equivalent structural drawing.
Common mistakes: Using alkane formula CnH2n+2; Incorrect structure such as missing the double bond
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Marking points
B1 · 1 mark · States correct general formula for alkenes: CnH2n
B2 · 1 mark · Draws correct displayed formula of propene showing the double bond between carbons 1 and 2, with all atoms and bonds clearly marked.
Worked solution
The general formula for alkenes is CnH2n.
The displayed formula for propene is: