1 Compound B, shown below, is an antiviral medicine
i. What is the molecular formula of compound B
[1]
ii. How many chiral carbon atoms are there in one molecule of compound B?
[1]
iii. A research chemist synthesises two related compounds, compound C and compound D, from compound B.
• In compound C, the N atoms in compound B had been replaced by P atoms.
• In compound D, the O atoms in compound B had been replaced by S atoms.
What is the difference between the relative molecular masses of compound C and compound D?
difference = ................................................... [2]
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, 2 Oil of wintergreen is a liquid used in medicine to relieve muscle pain.
Compound H is a component in oil of wintergreen and can be synthesised from compound G, as shown below.
The boiling point and density of compound H are stated.
A student prepares a sample of compound H by the method below.
Step 1 Reflux 8.97 g of compound G for 30 minutes with an excess of methanol in the presence of a small
amount of sulfuric acid as a catalyst.
Step 2 Add an excess of aqueous sodium carbonate, Na2CO3(aq). Two layers are obtained.
Step 3 Purify the impure compound H that forms from the resulting mixture.
The student follows this method and obtains 5.32 g of pure compound H.
Why does the student use reflux in Step 1?
[1]
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, 3 Complete the flowchart by filling in each box.
[9]
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, 4(a) The repeat unit of a polyester is shown below.
Draw the structures of monomers required to form this polyester.
[2]
(b) The compound below contains an ester and an amide group.
Draw the structures of the organic products formed by the complete alkaline hydrolysis of this compound using
NaOH(aq).
[4]
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i. What is the molecular formula of compound B
[1]
ii. How many chiral carbon atoms are there in one molecule of compound B?
[1]
iii. A research chemist synthesises two related compounds, compound C and compound D, from compound B.
• In compound C, the N atoms in compound B had been replaced by P atoms.
• In compound D, the O atoms in compound B had been replaced by S atoms.
What is the difference between the relative molecular masses of compound C and compound D?
difference = ................................................... [2]
© OCR 2025. You may photocopy this page. 1 of 151 Created in ExamBuilder
, 2 Oil of wintergreen is a liquid used in medicine to relieve muscle pain.
Compound H is a component in oil of wintergreen and can be synthesised from compound G, as shown below.
The boiling point and density of compound H are stated.
A student prepares a sample of compound H by the method below.
Step 1 Reflux 8.97 g of compound G for 30 minutes with an excess of methanol in the presence of a small
amount of sulfuric acid as a catalyst.
Step 2 Add an excess of aqueous sodium carbonate, Na2CO3(aq). Two layers are obtained.
Step 3 Purify the impure compound H that forms from the resulting mixture.
The student follows this method and obtains 5.32 g of pure compound H.
Why does the student use reflux in Step 1?
[1]
© OCR 2025. You may photocopy this page. 2 of 151 Created in ExamBuilder
, 3 Complete the flowchart by filling in each box.
[9]
© OCR 2025. You may photocopy this page. 3 of 151 Created in ExamBuilder
, 4(a) The repeat unit of a polyester is shown below.
Draw the structures of monomers required to form this polyester.
[2]
(b) The compound below contains an ester and an amide group.
Draw the structures of the organic products formed by the complete alkaline hydrolysis of this compound using
NaOH(aq).
[4]
© OCR 2025. You may photocopy this page. 4 of 151 Created in ExamBuilder
