JC 2 Preliminary Examination
CHEMISTRY
9647/03
Higher 2
13 September 2010
Paper 3 Free Response
2 hours
Candidates answer on separate paper.
Additional Materials: Answer paper, Graph Paper, Data Booklet
READ THESE INSTRUCTIONS FIRST
Write your name and civics group on all the work you hand in.
Write in dark blue or black pen on both sides of the paper.
You may use a soft pencil for any diagrams, graphs or rough working.
Do not use staples, paper clips, highlighters, glue or correction fluid.
Answer any four questions.
A Data Booklet is provided.
You are reminded of the need for good English and clear presentation in your answers.
The number of marks is given in brackets [ ] at the end of each question or part question.
At the end of the examination, fasten all your work securely together.
2
This question paper consists of 10 printed pages.
SAJC 2010 P3 – Answer any four questions.
1
(a) Hydrolysis of a lipid (containing multiple ester linkages) produced the following fatty acids. Structure I
CH3(CH2)4CH=CHCH2CH=CH(CH2)7COOH
Structure II
CH3CH2CH=CHCH2CH=CHCH2CH=CH(CH2)7COOH
(i) In an experiment, hot acidified potassium manganate(VII) was used to oxidise
Structure I. Write the structural formulae of all organic products formed during the oxidation. (ii) What is meant by the term cis-trans isomerism? How many cis-trans isomers are present in Structure I? Draw any 2 possible cis-trans isomers.
(iii) State the physical state of this lipid at room temperature. Explain your answer.
[9]
(b) Suggest a possible identity for each of the organic compounds A-E below. Explain your reasoning and write balanced equations for the reactions involved where possible.
(i) A, C11H14O2 is a neutral compound. Hydrolysis of A gives B, C7H6O2 which is a white precipitate and C, C4H10O which does not decolourise acidified potassium manganate(VII) on heating.
(ii) D, C4H10O2 reacts with 2