Unit 1B: Carbonyl compounds test
1)
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2)
Propanal, CH3CH2CHO, can be used in the synthesis of organic compounds.
CH3CH2CHO reacts with NaBH4 in a nucleophilic addition reaction. The nucleophile can be
represented as a hydride ion, H–. A mechanism for the reaction is shown below.
H
+
H
NaBH4
step 1
C
H
H
(i)
O –
O–
O
CH3C H2
+
CH3CH2
C
H
step 2
H
organic product
–
Add 'curly arrows' to the mechanism to show how the intermediate reacts with the
water molecule in step 2.
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(ii)
Draw the structure of the organic product in the box above.
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(iii)
What is meant by the term nucleophile?
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(iv)
3)
Describe, in words, exactly what is happening to the electron pairs and bonds in step
1 of the mechanism above.
[3]
Glyceryl trihexanoate is a triglyceride that can be made from glycerol
(propane-1,2,3-triol) and hexanoic acid, C5H11COOH.
a) Draw the structure of glyceryl trihexanoate. Show every bond in the functional groups.
[2]
b) Naturally occurring glyceryl tritrihexanoate is found in vegetable oil. It can be used to
produce biodiesel using transesterification. Write a chemical equation outlining the reaction,
giving all reagents necessary.
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4)
As a wine ages, some of the carboxylic acids slowly react with ethanol in the wine to
produce esters.
(i)
Draw a displayed formula to show the structure of the ester formed when propanoic
acid reacts with ethanol.
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(ii)
Suggest what effect this process might have on the flavour of the wine. Explain your
reasoning.
[1]
5)
Compound A is used to add the flavour of mushrooms to foods.
O
C
H 3C
C
H
CH2
O
C
CH3
compound A
(a)
(i)
Apart from the benzene ring, name the two functional groups in compound A.
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(ii)
Draw the skeletal formula of compound A.
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(iii) Deduce the molecular formula of compound A.
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(b)
If the food is cooked for a long time, naturally occurring acids catalyse the hydrolysis
of compound A.
Draw structures to show the two organic compounds formed by the acid hydrolysis of
compound A.
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