Displayed formulae
3 marks · EasyDraw the displayed formula for propene (\ce{C3H6}\)).
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
Must show: Three carbon atoms connected in a chain, A carbon-carbon double bond between two carbons, Each carbon atom forms four bonds in total, Each hydrogen forms one bond
Also accept: C=C-C orientation either left or right; hydrogens may be placed above or below so long as rules are obeyed
Common mistakes: Drawing an alkane instead of an alkene (all single bonds); Incorrect number of hydrogens
Show mark scheme and worked solution
Marking points
B1 · 1 mark · Correct carbon skeleton with three carbons in a chain.
B2 · 1 mark · Correct placement of the carbon-carbon double bond (between C1 and C2 or C2 and C3).
B3 · 1 mark · All other bonds shown: hydrogens correctly attached, each carbon forms four bonds.
Worked solution
Place a double bond between any two adjacent carbons. Each C has four bonds, each H has one.