Types of formula for organic molecules
4 marks · NormalPropene is an organic molecule. Use the information to answer the following:
State the molecular formula of propene.
Write the empirical formula of propene.
Draw the displayed formula for propene.
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) C3H6
(b) CH2
(c) Displayed formula for propene: H H H | | | H–C=C–C–H | | H H or equivalent correct drawing with double bond.
Must show: C3H6, CH2, Displayed formula with double bond between two carbons and correct number of hydrogens
Common mistakes: Incorrect molecular formula; Confusing empirical with molecular formula; Missing double bond in displayed formula
Show mark scheme and worked solution
Marking points
B1 (a) · 1 mark · Molecular formula is correct: C3H6.
B2 (b) · 1 mark · Empirical formula given is correct: CH2.
B3 (c) · 1 mark · Attempts structure with three carbon atoms joined, with a double bond between two carbons.
B4 (c) · 1 mark · Correctly completes H atoms for all carbons.
Worked solution
a) The molecular formula of propene is C3H6.
b) The empirical formula is CH2.
c) The displayed formula is: