OCR A Level Chemistry B (Salters) Fundamentals of chemistry June 2022 question paper H433/01

Which feature of the structure of the atom was deduced from the Geiger and Marsden experiment?

A Atoms consist of electrons, protons and neutrons.

B The nucleus is small and dense.

C Electrons exist in energy levels/shells.

D Electrons exist in atomic orbitals.

Which row gives the correct trends for the following properties of Group 2 elements and compounds going down the Group?

The bar chart shows the melting points of the elements in Periods 2 and 3. What is the correct reason for the large decrease in melting point after Group 14 in both Periods?

A The bonding of the elements changes from metallic to covalent.

B The elements change from metals to non-metals.

C The structure and bonding of the elements change from ionic to simple molecular.

D The structure of the elements changes from giant to molecular.

What is the correct bond angle in the ammonia molecule?

A 90°

B 107°

C 109°

D 120°

In which of the following reactions is iodine oxidised?

Which mixture forms a buffer solution?

A A mixture of a strong acid and a strong base

B A mixture of a strong acid with its salt

C A mixture of a strong base with its salt

D A mixture of a weak acid with its salt

What is correct about the greenhouse effect?

A Carbon dioxide is the only gas in the troposphere that acts as a greenhouse gas.

B Infrared radiation breaks bonds in molecules in the troposphere.

C The main way that the Earth is heated is by infrared radiation from the Sun.

D The Earth emits infrared radiation.

What is correct about nitrogen chemistry?

A The ammonia molecule has a lone pair of electrons.

B The ammonium ion has a bond angle of 120°.

C The ammonium ion has four dative covalent bonds.

D The nitrogen molecule has a double bond.

Which row is correct?

Ammonia is manufactured using the process shown in Equation 10.1.

A high pressure and moderate temperature are used.

What is correct about this manufacturing process?

A Creating a high pressure is expensive and dangerous.

B If the process were attempted at room temperature it would be quicker but give less ammonia.

C The nitrogen gas is expensive.

D The process is beneficial to society because it removes nitrogen from the air.

Which of the following alcohols cannot undergo dehydration?

A CH₃CH₂CH₂CH₂OH

B (CH₃)₂CHCH₂OH

C (CH₃)₃COH

D CH₃CH(OH)CH₂CH₃

Which equation represents the first ionisation enthalpy of phosphorus?

Predict which row is correct for selenium, Se.

What is the correct order of boiling points?

A CH₃CH₂COOH > CH₃CH₂CH₂OH > CH₃CH₂CHO

B CH₃CH₂COOH > CH₃CH₂CHO > CH₃CH₂CH₂OH

C CH₃CH₂CH₂OH > CH₃CH₂COOH > CH₃CH₂CHO

D CH₃CH₂CHO > CH₃CH₂COOH > CH₃CH₂CH₂OH

What is the correct M_r value of the organic molecule whose mass spectrum is shown below?

What is correct about the linking of DNA strands?

A Adenine forms three hydrogen bonds with thymine.

B Guanine forms three hydrogen bonds with cytosine.

C Guanine forms two hydrogen bonds with adenine.

D Uracil forms two hydrogen bonds with adenine.

The Kekulé structure of benzene (C₆H₆) is shown below.

What is a correct statement about benzene if the Kekulé structure represented the actual structure and bonding in benzene?

A The molecule would have a regular hexagonal shape.

B The molecule would undergo electrophilic substitution reactions.

C The molecule would form several different compounds of formula C₆H₄Br₂.

D The molecule would decolorise bromine water.

A dye molecule is shown below.

What is correct about this dye molecule?

A Delocalisation extends over the whole dye molecule.

B The dye molecule will attach itself to fibres mainly by covalent bonds.

C Substitution of CH₃ groups onto a ring will increase the solubility of the dye in water.

D Substitution of NO₂ groups onto a ring will not affect the chromophore.

What is correct about a 0.1 mol dm^–3 solution of a strong base? 19

[OH^–] << 0.1 mol dm^–3. A

The solution is weaker than a 0.5 mol dm^–3 solution of the same base. B

C The pH of the solution is given by pH = 14 + log₁₀(0.1) at 298 K.

D The solution will not react with weak acids.

GCC is a mRNA triplet code for alanine.

What is correct?

A Alanine has a transfer RNA with the code CGG.

B GCC is the only code for alanine.

C Other amino acids as well as alanine are coded by GCC.

D The mRNA sequence is produced by GCC on a DNA strand.

10 cm³ of 0.10 mol dm^–3 HCl (aq) is added to 5 cm³ of 0.10 mol dm^–3 NaOH(aq). 23

What is the pH of the resulting solution?

A 1.0

B 1.2

C 1.3

D 1.5

Ethanoic acid is a weak acid and hydrochloric acid is a strong acid.

What is correct about 10 cm³ of 0.1 mol dm^–3 solutions of each acid?

A They both fizz at the same rate with equal sized pieces of magnesium.

B They both fizz at the same rate with equal sized pieces of CaCO₃.

C They both have the same effect on pH indicator paper.

They both neutralise 10 cm³ of 0.1 mol dm^–3 NaOH(aq). D

The formation of an azo dye is shown in Reaction 25.1 below.

What is correct about this reaction and the compounds involved?

A Compound Y can be formed by a diazotisation reaction on the compound below.

B Reaction 25.1 is a coupling reaction between diazonium groups and NH groups.

C Reaction 25.1 is an addition reaction.

D Reaction 25.1 needs cold HNO₂.

Manganate(VII) ions react with sulfate(IV) ions as shown in the unbalanced equation below.

What is the ratio of SO₄^2–(aq): H₂O(l) in the balanced equation?

A 1:1

B 1:3

C 3:4

D 5:3

Iodine is formed from iodide ions by reaction with copper(II) ions as shown in the following ionic equation.

The iodine formed can be titrated with sodium thiosulfate as shown in the following ionic equation.

25.0 cm³ of a copper(II) solution forms iodine that reacts with 22.5 cm³ of 1.50 × 10^–2 mol dm^–3 sodium thiosulfate solution.

What is the concentration of copper(II) ions (in mol dm^–3) in the solution?

3.38 × 10^–4 A

6.75 × 10^–3 B

1.35 × 10^–2 C

2.70 × 10^–2 D

Which statement(s) is/are correct about an orange dye?

1 Blue light is absorbed when electrons rise to higher energy levels.

2 Orange light is emitted when electrons drop to lower energy levels.

3 The dye absorbs orange light.

A 1, 2 and 3

B Only 1 and 2

C Only 2 and 3

D Only 1

Which statement(s) is/are correct about nitrogen chemistry?

1 Ammonium compounds give off ammonia when warmed with alkalis.

3 Nitrate(V) ions can be oxidised to nitrate(III) ions.

A 1, 2 and 3

B Only 1 and 2

C Only 2 and 3

D Only 1

Bromine is currently extracted from the Dead Sea.

Bromine is made from the sodium bromide present in sea water.

Complete the table showing the structure, bonding and properties of bromine and sodium

The extraction process for bromine involves bubbling chlorine gas through sea water.

The equation for the reaction is shown below.

Explain in terms of electrons why chlorine can displace bromine from bromide ions.

Bromine can also be produced by the electrolysis of aqueous sodium bromide.

Write the ionic half-equation for the production of bromine at the anode.

A solution contains 2.57 g dm^–3 of sodium bromide. (d)

Calculate the minimum volume of chlorine gas (in cm³) required at 20 °C and 101 kPa to displace all the bromine from 100 cm³ of this solution.

Three test-tubes, labelled as A, B and C, contain solutions of sodium chloride, sodium bromide and sodium iodide but not necessarily in that order. A student adds an equal volume of silver nitrate solution to each tube.

Tubes A and B both give precipitates that are not white but are not clearly distinguishable from each other. Tube C gives a white precipitate.

Write an ionic equation for the reaction that has occurred in tube C.

Show state symbols.

Describe what the student would do to the precipitates to distinguish between the halide ions in tubes A and B.

State the expected results.

Another student tries to prepare a sample of pure hydrogen bromide by adding concentrated sulfuric acid to solid sodium bromide. A brown vapour is produced as well as fumes of HBr.

Write an equation to show why a brown vapour is produced when hydrogen bromide reacts with sulfuric acid.

State how the student can produce pure hydrogen bromide.

The Montreal Protocol was established to phase out ozone-depleting CFCs. CFC molecules contain carbon, fluorine and chlorine atoms only. When CFCs reach the stratosphere they decompose, releasing atoms that cause ozone to break down.

A student says that when CFCs decompose they release F atoms. This is because the C–F bond is more polar than the C–C l bond and breaks more easily.

Comment on the statements made by the student. Give and explain the correct chemistry where necessary.

Nitrogen oxides from aircraft exhausts can also play a part in ozone depletion.

Nitrogen dioxide undergoes photodissociation by homolytic bond fission according to the following equation.

Photodissociation occurs with ultraviolet radiation with a wavelength of 3.96 × 10^–7 m.

Calculate the enthalpy of the N–O bond (in kJ mol^–1) that breaks in NO₂.

Give your answer to an appropriate number of significant figures.

enthalpy of N–O bond =........ kJ mol^–1

The NO radical can act as a homogeneous catalyst in a catalytic cycle that depletes ozone.

Explain what is meant by the term homogeneous as applied to a catalyst.

The NO radical depletes ozone in a catalytic cycle. The first reaction in the cycle is shown below.

Suggest an equation to complete the cycle.

Explain how a catalyst increases the rate of a reaction.

Radical reactions are also important in making haloalkanes.

The reaction between methane and chlorine to make chloromethane occurs according to the following equation:

The product mixture is also found to contain other compounds, including small amounts of a chloroalkane D with M_r = 85 and a hydrocarbon E with M_r = 30.

Identify the compounds D and E.

D is........ E is........

Use your knowledge of the stages of the mechanism of Reaction 32.1 to suggest equations showing how D and E are formed.

Parabens are used as antifungal preservatives in cosmetic products like shaving gel. Parabens are esters of 4-hydroxybenzoic acid, HOC₆H₄COOH (4-HBA).

4-HBA is a white solid.

The antifungal properties of parabens are linked to their solubility in fats (esters of propane-1,2,3-triol).

Suggest the intermolecular bonds that cause parabens (esters of 4-HBA) to be soluble in fats.

A student shakes some 4-HBA with sodium hydroxide solution.

A reaction occurs forming a soluble product.

Write the equation for the reaction of solid 4-HBA, HOC₆H₄COOH, with excess sodium hydroxide solution.

Show state symbols.

The student places some aqueous sodium carbonate into a test-tube and adds small quantities of 4-HBA.

Describe two things that the student would observe.

Write a formula for the organic product that is formed when 4-HBA reacts with aqueous sodium carbonate.

The student prepares an impure sample of ethyl paraben by reacting 4-HBA with ethanol.

Describe how the student could purify the ethyl paraben.

You should make use of the solubility data for ethyl paraben in Table 33.1 below.

4-HBA reacts with thionyl chloride to make HOC₆H₄COCl.

Give the name of the functional group COC l that is formed in this reaction.

Give the structural formula of the aromatic product formed in the reaction between HOC₆H₄COCl and CH₃NH₂.

Methanol is an important alcohol that can be used for making various plastics and it can also be used as a fuel. It can be produced industrially by reacting carbon monoxide with hydrogen according to the equilibrium in Equation 34.1.

Student F says that dynamic equilibrium is reached when the forward and back reactions are still occurring and the concentrations of the reactants and products are equal.

Student G says that equilibrium is reached when the forward and back reactions have stopped.

Evaluate these two statements giving correct chemistry where necessary.

* The most economic operating conditions for the manufacture of methanol are a temperature of 525 K and a pressure of 40 atm with a copper-based catalyst.

Discuss these conditions.

Use the principles of equilibrium and rates of reaction and give the supporting chemistry.

Another important industrial process is the one that produces hydrogen from methane as shown in Equation 34.2.

State and explain the sign of _sysS for the reaction in Equation 34.2.

Calculate the temperature (in K) at which the reaction in Equation 34.2 is just feasible.

You should make use of the data in Table 34.1 below.

Local anaesthetics work by binding to certain receptors in cells in order to inhibit pain.

Name the part of a molecule that binds to a receptor in a cell in the body.

A synthesis of benzocaine occurs in several stages.

A first step involves the conversion of benzene into methylbenzene as shown in the equation

The benzene is heated with chloromethane and aluminium(III) chloride as a catalyst in anhydrous conditions.

Explain why this reaction must be carried out in anhydrous conditions.

Name the mechanism of the reaction involved in this first step.

Further reactions are then carried out to convert methylbenzene into 4-aminobenzoic acid.

4-aminobenzoic acid

Complete the following equation to show a synthesis of benzocaine from 4-aminobenzoic acid.

An alternative route to 4-aminobenzoic acid involves the following three-step reaction sequence.

4-nitrobenzoic acid
4-aminobenzoic acid

Give the reagents and conditions that a student could use to bring about the reaction in Step 1.

The conversion in Step 1 occurs through the intermediate formation of benzaldehyde.

Describe a test-tube reaction that a student could carry out to test for the aldehyde group in benzaldehyde.

The reaction of benzaldehyde with hydrogen cyanide can be written as follows:

Write out the two-step mechanism for this reaction.

Use ‘curly arrows’ and partial and full charges.

In Step 2, the benzoic acid is reacted with a nitrating mixture of concentrated nitric and concentrated sulfuric acids.

Write an equation to show the formation of the electrophile in this reaction.

The conversion in Step 3 is brought about by heating 4-nitrobenzoic acid with tin and concentrated hydrochloric acid under reflux.

Explain why the heating is carried out under reflux.

The skeletal formula for another local anaesthetic, lidocaine, is shown below.

Draw the skeletal formulae of the two products formed from the alkaline hydrolysis of the amide group in lidocaine.

Product 1
Product 2

* A molecule of another aromatic compound H is found to contain 72.0% carbon, 6.67% hydrogen and 21.3% oxygen by mass.

The M_r of H is 150.

The¹³C NMR spectrum of H is shown below.

The¹H NMR spectrum of H is shown below.

You may do working on this page but it will not be marked.

Use the data on page 34 to identify compound H.

Give evidence from the percentage composition and the two spectra.