Chemistry — Modular 2024, Unit 2

Practice Paper 1 (Edexcel IGCSE Chemistry)

Exam code:4XCH1

14 questions · 62 marks · ≈ 62 min · spans 14 of 14 topics

Assembled from the topic question banks — not an official Edexcel paper

Guided practice

11 markeasy

Air is a mixture of gases.

What is the approximate percentage of nitrogen in air?

Choose your answer

21 markeasy

A student adds a few drops of dilute nitric acid followed by a few drops of silver nitrate solution to a test tube containing an unknown colourless solution. A white precipitate is seen.

What ions could be present in the solution?

Choose your answer

Ammonium ions

Chloride ions

Sulfate ions

Magnesium ions

31 markeasy

This question is about the reaction between sodium and water.

Which statement about this reaction is correct?

Choose your answer

Sodium sinks to the bottom of the water

A lilac flame is seen

A solution of sodium oxide is produced

Bubbles of hydrogen gas are produced

41 markmedium

Separate: Chemistry Only

The ionic equation for the reaction between chlorine and sodium bromide is:

Cl₂(g) + 2Br^–(aq) → 2Cl^–(aq) + Br₂(aq)

This reaction occurs because chlorine is more reactive than bromine.

Which of the statements explaining why chlorine is more reactive than bromine is not true?

Choose your answer

chlorine has smaller atoms than bromine

chlorine atoms gain electrons more easily

chlorine atoms lose electrons more easily

chlorine atoms have fewer electron shells than bromine atoms

58 markshard

1 mark

Separate: Chemistry Only

This question is about alcohols.

Alcohols have the general formula C_nH_2n+1OH.

Draw the displayed formula of propanol.

Your answer

1 mark

Separate: Chemistry Only

Deduce the molecular formula of the alcohol that has a relatvie molecular mass of 102.

Your answer

3 marks

Separate: Chemistry Only

Alcohols undergo combustion reactions.

Write a balanced symbol equation for the complete combustion of butanol.

Your answer

3 marks

Separate: Chemistry Only

Describe the conditions needed to convert ethene to ethanol.

Your answer

How did you do?/ 8

69 marksmedium

5 marks

This question is about carboxylic acids and esters.

A carboxylic acid has the empirical formula C₂H₄O.

The relative formula mass of the acid is M_{*r *}= 88.

i) Determine the molecular formula of the acid.

(2 marks)

ii) Draw the displayed formula of the carboxylic acid.

(1 mark)

iii) Name the acid.

(1 mark)

iii) Draw a ring around the functional group.

(1 mark)

Your answer

4 marks

i) Describe what you would see when a small piece of magnesium ribbon is added to a solution of the carboxylic acid.

(2 marks)

ii) Describe how you would identify any gaseous products.

(2 marks)

Your answer

How did you do?/ 9

716 marksmedium

2 marks

(a)

Separate: Chemistry Only

Ethanol, C₂H₅OH, can be oxidised to produce ethanoic acid, CH₃COOH, by heating it with potassium dichromate(VI).

i) Name one other reactant needed for this reaction to occur.

(1 mark)

ii) Which colour change occurs during this reaction?

(1 mark)

☐	A	colourless to green
☐	B	green to orange
☐	C	orange to colourless
☐	D	orange to green

Your answer

5 marks

(b)

Separate: Chemistry Only

When ethanol is burned in air, complete combustion can occur. The equation for this reaction is:

C₂H₅OH + 3O₂ → 2CO₂ + 3H₂O

This equation can also be written using displayed formulae to show all the covalent bonds in the molecules.

oxidation-of-ethanol

The table gives the bond energies for these bonds.

Bond	C-C	C-H	C-O	O-H	O=O	C=O
Bond energy in kJ / mol	346	412	358	463	496	743

i) Use values from the table to calculate the energy needed to break all the bonds in the reactants.

(2 marks)

energy needed .............................................................. kJ

ii) Use values from the table to calculate the energy released when all the bonds in the products are formed.

(2 marks)

energy released .............................................................. kJ

iii) Calculate the molar enthalpy change (ΔH) in kJ / mol, for the complete combustion of ethanol. Include a sign in your answer.

(1 mark)

ΔH = .............................................................. kJ / mol

Your answer

5 marks

(c)

Separate: Chemistry Only

Ethanol reacts with methanoic acid, HCOOH, in the presence of an acid catalyst to form an ester.

The equation for the reaction is:

C₂H₅OH + HCOOH $\rightleftharpoons$ HCOOC₂H₅ + H₂O

i) Give the name of the ester that forms.

(1 mark)

ii) Draw the displayed formula for this ester.

(2 marks)

iii) When this reaction takes place in a sealed container, the reaction can reach dynamic equilibrium.

Give two characteristics of a reaction at dynamic equilibrium.

(2 marks)

Your answer

4 marks

(d)

Separate: Chemistry Only

Methanoic acid reacts with sodium carbonate to form sodium methanoate, carbon dioxide and water.

The equation for the reaction is:

2HCOOH + Na₂CO₃ → 2HCOONa + CO₂ + H₂O

Calculate the volume, in cm³ , of carbon dioxide gas produced when 2.3 g of methanoic acid reacts completely with sodium carbonate.

[M_r of HCOOH = 46]

[Molar volume of carbon dioxide at rtp = 24 dm³]

volume of carbon dioxide = .............................................................. cm³

Your answer

How did you do?/ 16

81 markeasy

Which statement is the correct description of a polymer?

Choose your answer

The atoms within a monomer

A large saturated hydrocarbon

A large molecule made from many small molecules

A large unsaturated molecule

91 markeasy

Which of these statements about catalysts is not correct?

Choose your answer

The mass of the catalyst at the start of the reaction is the same at the end of the reaction

Catalysts increase the rate of reaction but do not increase the yield

Catalysts are not chemically changed during the course of the reaction

Catalysts provide an alternative reaction pathway which has a lower activation energy

109 markshard

6 marks

(a)

Separate: Chemistry Only

Ammonia is manufactured on a large scale and is used to make fertilisers such as ammonium nitrate (NH₄NO₃).

The first stage in the manufacture of ammonium nitrate is to react ammonia gas with oxygen gas.

4NH₃ (g) + 5O₂ (g) $\rightleftharpoons$ 4NO (g) + 6H₂O (g) ΔH = −907 kJ/mol

The reaction is carried out at a pressure of about 10 atm and at a temperature of 800 °C, in the presence of a catalyst.

If the mixture is left for long enough in a sealed container, the reaction reaches a position of dynamic equilibrium.

Graph A shows how the percentage of nitrogen monoxide (NO) in the equilibrium mixture varies with temperature at constant pressure.

Graph B shows how the percentage of nitrogen monoxide (NO) in the equilibrium mixture varies with pressure at a constant temperature.

screen-shot-2022-10-12-at-20-31-25

i) Explain why the percentage of NO at equilibrium decreases in each case.

Graph A:

Graph B:

(4 marks)

ii) Explain why the use of a catalyst has no effect on the position of equilibrium in a reversible reaction.

(2 marks)

Your answer

3 marks

(b)

Separate: Chemistry Only

The second stage in the manufacture of ammonium nitrate is to convert the nitrogen monoxide into nitric acid. The nitric acid is then reacted with concentrated aqueous ammonia as shown in this equation.

HNO₃ (aq) + NH₃ (aq) → NH₄NO₃ (aq)

i) State, in terms of proton transfer, why this reaction is classified as an acid-base reaction.

(1 mark)

ii) Calculate the volume of 14.8 mol/dm³ aqueous ammonia that is required to exactly neutralise 150 dm³ of a solution of nitric acid of concentration 15.8 mol/dm³.

(2 marks)

Your answer

How did you do?/ 9

111 markmedium

Carbon dioxide contains covalent bonds.

The covalent bonds in a molecule of carbon dioxide can be represented by a dot-and-cross diagram.

Which is the correct dot-and-cross diagram for carbon dioxide?

Choose your answer

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121 markeasy

Separate: Chemistry Only

A student uses the apparatus to electrolyse an aqueous solution of copper(II) sulfate.

1-9-q1-edexcel-igcse-chemistry

Which substances are formed at the negative electrode (cathode) and the positive electrode (anode)?

Choose your answer

Negative electrode: hydrogen Positive electrode: sulfur

Negative electrode: copperPositive electrode: oxygen

Negative electrode: sulfur Positive electrode: hydrogen

Negative electrode: oxygen Positive electrode: copper

137 markseasy

4 marks

Sodium chloride is an ionic compound which is soluble in water. Sodium ions and chloride ions bond together forming an ionic lattice.

i) Explain how a sodium atom becomes a sodium ion.

(2 marks)

ii) Explain how a chlorine atom becomes a chloride ion.

(2 marks)

Your answer

1 mark

Which of the following explains why sodium fluoride is soluble in water.

Tick (✓) one box.

Both ionic compounds and water are polar substances
Ionic compounds have weak bonds
Water has weak bonds

Your answer

1 mark

Sodium fluoride has a melting point 993 °C. Why does sodium fluoride have a high melting point.

Tick (✓) one box.

The electrons and positive ions attract strongly
The covalent bonds between the ions are strong
There are strong bonds between the positively and negatively charged ions

Your answer

1 mark

Sodium fluoride can conduct electricity when either molten or in solution. Why can sodium fluoride only conduct electricity when molten or in solution.

Tick (✓) one box.

Electrons can move and carry a charge
Ions can move and carry a charge
Electrons can flow throughout the ionic lattice

Your answer

How did you do?/ 7

145 markseasy

Aluminium is an element found in Group 3 of the Periodic Table.

Use your Periodic Table to deduce the number of protons, neutrons and electrons found in an atom of aluminium.

		protons	neutrons	electrons
☐	A	13	27	13
☐	B	13	27	14
☐	C	27	14	14
☐	D	13	14	13

Choose your answer

Option A

Option B

Option C

Option D

2 marks

Separate: Chemistry Only

Give two physical properties of aluminium.

Your answer

Separate: Chemistry Only

Duralumin is an alloy of aluminium and copper. What type of substance is an alloy?

Choose your answer

Atom

Element

Compound

Mixture

1 mark

Aluminium is extracted from bauxite, a mixture containing aluminium oxide.

One sample of bauxite contains 17% aluminium. Calculate the percentage of substances other than aluminium found in bauxite.

Your answer

How did you do?/ 5

☐

colourless to green

☐

green to orange

☐

orange to colourless

☐

orange to green

Bond

C-C

C-H

C-O

O-H

O=O

C=O

Bond energy in kJ / mol

346

412

358

463

496

743

109 markshard

6 marks

(a)

Separate: Chemistry Only

Ammonia is manufactured on a large scale and is used to make fertilisers such as ammonium nitrate (NH₄NO₃).

The first stage in the manufacture of ammonium nitrate is to react ammonia gas with oxygen gas.

4NH₃ (g) + 5O₂ (g) $\rightleftharpoons$ 4NO (g) + 6H₂O (g) ΔH = −907 kJ/mol

The reaction is carried out at a pressure of about 10 atm and at a temperature of 800 °C, in the presence of a catalyst.

If the mixture is left for long enough in a sealed container, the reaction reaches a position of dynamic equilibrium.

Graph A shows how the percentage of nitrogen monoxide (NO) in the equilibrium mixture varies with temperature at constant pressure.

Graph B shows how the percentage of nitrogen monoxide (NO) in the equilibrium mixture varies with pressure at a constant temperature.

screen-shot-2022-10-12-at-20-31-25

i) Explain why the percentage of NO at equilibrium decreases in each case.

Graph A:

Graph B:

(4 marks)

ii) Explain why the use of a catalyst has no effect on the position of equilibrium in a reversible reaction.

(2 marks)

Your answer

3 marks

(b)

Separate: Chemistry Only

HNO₃ (aq) + NH₃ (aq) → NH₄NO₃ (aq)

i) State, in terms of proton transfer, why this reaction is classified as an acid-base reaction.

(1 mark)

ii) Calculate the volume of 14.8 mol/dm³ aqueous ammonia that is required to exactly neutralise 150 dm³ of a solution of nitric acid of concentration 15.8 mol/dm³.

(2 marks)

Your answer

How did you do?/ 9

Both ionic compounds and water are polar substances

Ionic compounds have weak bonds

Water has weak bonds

The electrons and positive ions attract strongly

The covalent bonds between the ions are strong

There are strong bonds between the positively and negatively charged ions

Electrons can move and carry a charge

Ions can move and carry a charge

Electrons can flow throughout the ionic lattice

protons

neutrons

electrons

☐