OCR A Level Chemistry A Synthesis and analytical techniques June 2022 question paper H432/02

Which statement is correct for the different rates of hydrolysis of RC l and RBr?

A RBr is hydrolysed faster because C l is more electronegative than Br.

B RBr is hydrolysed faster because the C–C l bond enthalpy is greater than C–Br.

C RC l is hydrolysed faster because C l is more electronegative than Br.

D RC l is hydrolysed faster because the C–Br bond enthalpy is greater than C–C l.

Which statement about absorption of radiation is correct?

A Infrared radiation can result in the breakdown of the ozone layer.

B Ultraviolet radiation can cause some polymers to photodegrade to benefit the environment.

C Ultraviolet radiation is linked to global warming.

D Ultraviolet radiation is used in modern breathalysers to measure ethanol in the breath.

What is the number of sigma bonds in a molecule of methylbenzene?

A 7

B 10

C 12

D 15

The skeletal formula of an organic compound is shown below.

Which functional groups are present?

A amide and alcohol

B amide and carboxylic acid

C amine and carboxylic acid

D amine, ketone and alcohol

The structure of a drug is shown below:

How many chiral carbon atoms are there in a molecule of the drug?

A 5

B 6

C 7

D 8

Complete combustion of 0.050 mol of an alkane produces 5.40 g of H₂O.

What is the molecular formula of the alkane?

A C₂H₆

B C₃H₈

C C₄H₁₀

D C₅H₁₂

The structure of the painkiller, paracetamol, is shown below.

A tablet contains 3.31 × 10^–3 mol of paracetamol.

What is the mass of paracetamol in the tablet?

A 493 mg

B 497 mg

C 500 mg

D 506 mg

Butyl propanoate is hydrolysed by aqueous sodium hydroxide.

Which compound is one of the products of this hydrolysis?

A C₃H₇ONa

B C₃H₅O₂Na

C C₄H₉ONa

D C₄H₇O₂Na

The infrared spectrum of an organic compound is shown below.

Which compound could have produced this spectrum?

A H₂C=CHCH₂CH₂OH

B CH₃COOCH₂CH₃

C H₂NCH₂COOCH₃

D (CH₃)₂CHCONH₂

Which compound produces two triplets in its¹H NMR spectrum?

A CH₃CH₂COOCH₂CH₃

B CH₃CH₂COCH₂CH₃

C HOOCCH₂CH₂COOH

D HOOCCH₂CH₂CH₂COOH

Which equation(s) could be part of the propagation step in the radical substitution of C₅H₁₂ to form C₅H₁₁Cl ?

A 1, 2 and 3

B Only 1 and 2

C Only 2 and 3

D Only 1

Which species could react as a nucleophile?

2 OH –

A 1, 2 and 3

B Only 1 and 2

C Only 2 and 3

D Only 1

Which isomer(s) of C₅H₁₂O has/have 4 peaks in its/their¹³C NMR spectrum?

1 3-methylbutan-2-ol

2 2-methylbutan-2-ol

3 2-methylbutan-1-ol

A 1, 2 and 3

B Only 1 and 2

C Only 2 and 3

D Only 1

This question is about unsaturated hydrocarbons.

What is the systematic name of hydrocarbon A ?

Compounds B and C are branched hydrocarbons that are structural isomers of C₆H₁₂.

Compounds B and C both have stereoisomers.

• Compound B has cis and trans isomers but does not have optical isomers.

• Compound C has optical isomers but does not have cis and trans isomers.

What is meant by the term structural isomers ?

What is meant by the term stereoisomers ?

Draw structures for the cis and trans isomers of the branched hydrocarbon B.

Draw 3D structures for the optical isomers of compound C.

Compounds D and E are two more structural isomers of C₆H₁₂.

Compounds D and E do not show stereoisomerism.

Table 16.1 shows NMR and infrared (IR) spectral data for D and E.

Draw the structures of D and E and explain how the spectral data in Table 16.1 provides evidence for the structures.

Draw the structures of the products you would expect from the ozonolysis of the two compounds below.

This question is about carbonyl compounds.

Describe a chemical test to confirm the presence of a carbonyl group.

How could the product of this test be used to identify the carbonyl compound?

Your answer should not include spectroscopy.

Describe a chemical test that would identify whether a carbonyl compound is an aldehyde.

Your answer should include the reagent and observations.

A student is provided with two unknown carbonyl compounds, F and G.

The compounds are analysed and found to have identical percentage compositions by mass: C: 62.07%; H: 10.34%; O: 27.59%

The mass spectra of the two compounds are shown below.

Use the results to identify the structures of the two compounds.

Include relevant peaks present in the mass spectrum of each compound.

This question is about compounds that contain the carboxylic acid functional group.

Carboxylic acids react with alkalis, metals and carbonates to form salts.

Write full equations for the following three reactions. Show structures for organic compounds.

• the reaction of propanoic acid with aqueous potassium hydroxide:

• the reaction of aqueous methanoic acid with magnesium:

• the reaction of the –amino acid, aspartic acid (R=CH₂COOH), with an excess of aqueous sodium carbonate, Na₂CO₃:

This part is about polymers derived from carboxylic acid monomers.

Poly(pent-3-enoic acid) is an addition polymer.

Draw the structure of pent-3-enoic acid and two repeat units of this polymer.

Butanedicarboxylic acid and 1,4-dihydroxy-2-methylbenzene react to form a condensation polymer.

Draw one repeat unit of this condensation polymer.

Three repeat units of a condensation polymer are shown below.

Draw the structure of the monomer required to form this polymer.

A polymer is formed from 400 molecules of 2-aminopropanoic acid.

Draw one repeat unit of this polymer.

What is the relative molecular mass, M_r, of the polymer?

This question is about the chemistry of aromatic compounds.

What chemical test(s) could be used to confirm the presence of the phenol group in compounds K and L ?

A student thought that¹³C NMR spectroscopy could be used to distinguish between compounds J, K and L.

Explain, with reasoning, whether the student is correct.

Compound J is substituted at the 2-and 4-positions by chlorine in the presence of a catalyst.

Outline the mechanism for the 4 substitution of compound J by chlorine in the presence of a catalyst.

Show the role of the catalyst.

Compounds K and L react with chlorine much more readily than compound J.

Explain why.

Compound J, C₆H₅CH₂CH₂OH, is reacted with acidified potassium dichromate(VI) under reflux to form organic product M.

Write an equation for this reaction.

Use [O] to represent the oxidising agent and show the structure of M.

A two-stage synthesis of an amine from compound J is shown below.

Add the reagents for each stage of this synthesis.

Compound J

21* Carbon-carbon bond formation is used in synthesis to increase the length of a carbon chain.

Describe the formation of carbon–carbon bonds in aliphatic compounds by two different mechanisms.

Your answer should include mechanisms for each aliphatic compound.