Physical properties
3 marks · Easy(a)[1 mark]
Write the general formula for alkenes.
(b)[1 mark]
Write the molecular formula for the alkene with 7 carbon atoms.
(c)[1 mark]
How many hydrogen atoms are there in this molecule?
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) CnH2n
(b) C7H14
(c) 14
Common mistakes: Use of alkane formula; C7H14+2
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Marking points
B1 (a) · 1 mark · States correct general formula CnH2n
B2 (b) · 1 mark · Writes correct formula for n = 7: C7H14
B3 (c) · 1 mark · Gives 14 as number of hydrogen atoms
Worked solution
a) CnH2n
b) C7H14
c) There are 14 hydrogen atoms in the molecule.