IGCSEScienceEdexcelScience (Double Award) (Modular)Chemistry Unit 1Exam Questions1. Principles of Chemistry: Part 1States of matter

States of matter (Edexcel IGCSE Science (Double Award) (Modular): Chemistry Unit 1): Exam Questions

Exam code: 4XSD1

2 hours19 questions
Easy
Medium
Hard
1a
2 marks

This question is about states of matter.

The diagram shows how the particles of a substance are arranged in two different states.

Three identical empty square boxes side by side, labelled solid, liquid and gas. The solid box is filled to about one third of its height with circles packed in a regular arrangement in three rows, all touching. The liquid box is empty. The gas box contains five circles spread far apart from each other with large gaps between them.

i) Complete the diagram to show how particles are arranged in the liquid state.

[1]

ii) Identify the state of matter in which the particles have the most energy.

[1]

How did you do?

1b
3 marks

The state symbols (s), (l), (g) and (aq) are often used in chemistry. The table shows some physical changes. Complete the table by giving the state symbol before and after each change.

 

State symbol

Physical change

before change

after change

 water evaporates

 

 

 crystals of iodine sublime

 

 

 ice melts

 

 

How did you do?

1c
2 marks

Explain why hot water evaporates more quickly than cold water.

How did you do?

2a
3 marks

Some sugar is added to cold water in a beaker.

After some time, all the sugar dissolves and spreads throughout the water.

i) Name the process that occurs that causes the sugar to spread throughout the water.

[1]

ii) State two ways to make the sugar dissolve more quickly.

[2]

How did you do?

2b
3 marks

Pure water can be obtained from the sugar solution using this apparatus.

A simple distillation apparatus. On the left a round-bottomed flask, closed with a bung and holding a liquid, sits above an arrow labelled heat pointing upwards at it. A tube leads from the neck of the flask to the right into a long jacketed tube, which is labelled X by a leader line at its right-hand end. An arrow at the upper left of the jacket points outwards beside the label water out, and an arrow at the lower right of the jacket points inwards beside the label water in. The right-hand end of the jacketed tube slopes down into the mouth of a conical flask.

i) Name the process used to obtain pure water from the sugar solution.

[1]

ii) Explain the purpose of the piece of apparatus labelled X.

[2]

How did you do?

3a
2 marks

i) State the meaning of the term solute.

[1]

ii) State the meaning of the term solvent.

[1]

How did you do?

3b
2 marks

Explain what is meant by a saturated solution.

How did you do?

3c
2 marks

A dark purple liquid is diluted by adding water. 

The diluted liquid becomes a pale purple colour. 

Explain the process that causes this change. 

Refer to particles in your answer.

How did you do?

4
1 mark

The diagram shows a mirror in a bathroom. As the water vapour cools it turns into droplets of water on the bathroom mirror.

Line drawing of a bathroom. A rectangular mirror hangs on the wall on the left, labelled Mirror. To its right a shower head on a wall-mounted riser sprays droplets of water down into a free-standing roll-top bath with clawed feet. Wavy lines rise from the far end of the bath, labelled Water vapour.

When the water vapour changes to liquid water the change is called

  • vaporisation

  • condensation

  • sublimation

  • evaporation

Choose your answer

5
1 mark

The diagram below shows a bottle of perfume which has been sprayed in a room. Very soon the perfume can be smelled in every part of the room.

A round perfume bottle with a squeeze-bulb atomiser at its neck, drawn on the right. Three thin lines spray out to the left from the nozzle towards a cloud shape, representing perfume vapour spreading through the air. No labels on the diagram.

Which statement explains these observations?

  • The perfume particles diffuse into the air

  • The perfumes particles sublime into the air

  • The perfume particles are carried in air currents

  • The perfume particles are changing state

Choose your answer

6
1 mark

A crystal of potassium permanganate is placed in a beaker and left for a short time and a purple liquid is seen at the bottom of the beaker.

Two line diagrams of the same beaker of water, side by side. In the left-hand diagram, labelled Start, the water level is drawn about two thirds of the way up the beaker, the water is unshaded, and a large grey irregular lump resting on the base is labelled potassium permanganate crystal. In the right-hand diagram, labelled After a short time, the lump is much smaller and the bottom quarter of the beaker is shaded grey and labelled purple liquid, with the water above it still unshaded.

Which statement is correct?

  • Potassium permanganate solution is formed

  • Water is the solute

  • A saturated solution is formed

  • The crystal sublimes

Choose your answer

7a
2 marks

Substances can exist as solids, liquids or gases.

i) Give the change of state that occurs when a substance melts.

[1]

ii) Complete the word equation for the sublimation of iodine.

iodine (s) → iodine (...........)

[1]

How did you do?

7b
1 mark

The circle in the diagram represents a particle. Complete the diagram to show the arrangement of particles in a gas.

A square box outline with a single small empty circle drawn in the bottom left corner; the rest of the box is empty

How did you do?

7c
2 marks

The table lists some statements about particles. Place ticks (✓) in boxes to show which two statements are correct for water particles.

Statement

Tick

the particles only vibrate

the particles do not move

the particles have no gaps between them

the particles move randomly

the particles have more energy than in ice

the particles have a regular arrangement

How did you do?

8
1 mark

Substances exist as solids, liquids or gases.

Flow diagram showing solid, liquid and gas in a row. A pair of arrows, one pointing right and one pointing left, links solid and liquid and is unlabelled. A second pair of arrows links liquid and gas, with the arrow pointing from liquid to gas labelled Y and the arrow pointing from gas to liquid unlabelled.

What change of state occurs at Y?

  • Melting

  • Freezing

  • Boiling

  • Condensation

Choose your answer

9
1 mark

The diagram shows the three states of matter for a substance:

Three boxes labelled Solid, Liquid and Gas. In the Solid box, identical circles are packed touching each other in a regular grid of rows and columns, filling the lower half of the box with empty space above. In the Liquid box, circles of the same size are close together but randomly arranged, filling the whole box. In the Gas box, about ten widely separated circles are scattered throughout the box.

Which statement is correct about the movement or arrangement of the particles?

  • In the solid the particles move fast in all directions

  • In the gas the particles are close together

  • In the liquid the particles move randomly

  • In the liquid the particles vibrate about fixed positions

Choose your answer

10a
4 marks

This question is about states of matter.

The names of some terms are given in the box.

melting

deposition

evaporation

condensing

sublimation

freezing

boiling point

liquid

gas

Complete the table by choosing the term from the box that matches each description.

Each substance may be used once, more than once, or not at all.

Description

Substance

the state of ammonia at room temperature

when particles gain the most energy at constant temperature

particles break away from their fixed arrangement

when kerosene is produced from crude oil

How did you do?

10b
2 marks

Describe a test for ammonia.

How did you do?

1a
3 marks

This question is about the three states of matter, solid, liquid and gas.

Solids, liquids and gases can be changed from one state to another.

condensing

evaporation

melting

sublimation

Use words from the box to complete the sentences.

Each word may be used once, more than once or not at all.

i) The change from solid to liquid is called

[1]

ii) The change from liquid to gas is called

[1]

iii) The change from solid to gas is called

[1]

How did you do?

1b
3 marks

Describe the arrangement and the movement of particles in a solid.

How did you do?

2a
1 mark

This question is about ammonium chloride.

Give the formula of the ammonium ion.

How did you do?

2b
3 marks

Describe a test to show that ammonium chloride contains ammonium ions.

How did you do?

2c
1 mark

The equation shows the thermal decomposition of ammonium chloride.

NH4Cl(s) ⇌ NH3(g) + HCl(g)

State what the ⇌ symbol indicates about this reaction.

How did you do?

2d
4 marks

The diagram shows the formation of ammonium chloride in a glass tube.

A long horizontal glass tube drawn in cross-section, stoppered at each end with a grey bung. Just inside the left-hand bung is a ball of cotton wool, labelled cotton wool soaked in concentrated hydrochloric acid. Just inside the right-hand bung is an identical ball of cotton wool, labelled cotton wool soaked in concentrated ammonia solution. A narrow grey band spans the full height of the tube part way along it, labelled ammonium chloride, and it sits left of the midpoint of the tube, closer to the hydrochloric acid end

i) Explain how the mean speed of ammonia molecules compares with the mean speed of hydrogen chloride molecules.

[2]

ii) Gas particles travel very quickly. Give two reasons why it takes several minutes for the ammonium chloride to form.

[2]

How did you do?

3a
3 marks

The boxes list changes that may happen in a laboratory and the names of some changes.

Draw one straight line from each change to its correct name.

Two columns of boxes with no lines drawn between them. The left-hand column has three boxes, reading down the page: ice turns into water; solid carbon dioxide turns directly into a gas; a solute is stirred into a solvent. Each has a small dot on its right-hand edge. The right-hand column has six boxes, reading down the page: diffusion; dissolving; evaporation; freezing; melting; sublimation. Each has a small dot on its left-hand edge.

How did you do?

3b
3 marks

A student has two solids, X and Y.

One of these solids is a pure substance and the other is a mixture.

Describe how the student could identify which solid is pure and which is a mixture by measuring a physical property of each solid.

How did you do?

4a
3 marks

This question is about states of matter.

Use the words solid, liquid or gas to give the initial and final state of matter for each of the changes listed in the table.

The first one has been done for you.

Change

Initial state

Final state

 melting

solid

liquid

 sublimation

 

 

 condensing

 

 

 evaporation

 

 

How did you do?

4b
3 marks

Particles in a solid are closely packed, arranged in a regular pattern and vibrate about fixed positions.

Describe the arrangement and movement of the particles in a gas.

How did you do?

5a
3 marks

This question is about states of matter.

The box gives words relating to changes of state. 

condensation 

cooling 

evaporation

freezing 

melting 

sublimation

Complete the table by giving the correct word from the box for each change of state.

Change of state

Name of change

solid to liquid

 

solid to gas

 

liquid to solid

 

How did you do?

5b
4 marks

When ammonia gas and hydrogen chloride gas mix, they react together to form a white solid called ammonium chloride.

The equation for the reaction is

NH3 (g) + HCl (g) → NH4Cl (s)

A teacher soaks a piece of cotton wool in concentrated ammonia solution and another piece of cotton wool in concentrated hydrochloric acid.

The teacher places the two pieces of cotton wool at opposite ends of a glass tube at the same time.

After several minutes, a white ring of solid ammonium chloride forms.

A horizontal glass tube drawn in outline. A small grey cloud-shaped plug of cotton wool sits just inside the left-hand end, labelled cotton wool soaked in concentrated ammonia solution, and an identical plug sits just inside the right-hand end, labelled cotton wool soaked in concentrated hydrochloric acid. A narrow vertical band drawn across the tube between them, labelled white ring of ammonium chloride, is noticeably closer to the right-hand plug than to the left-hand one.

i) State the name given to the spreading out of gas particles.

[1]

ii) State how the diagram shows that the particles of ammonia gas are travelling at higher speeds than the particles of hydrogen chloride gas.

[1]

iii) Gas particles travel at high speeds.

Give a reason why the white ring of ammonium chloride takes several minutes to form.

[1]

iv) Concentrated ammonia solution and concentrated hydrochloric acid are corrosive.

Give one safety precaution the teacher should take.

[1]

How did you do?

6a
1 mark

Ammonium chloride decomposes in a reversible reaction. The equation for this reaction is

NH4Cl (s) ⇌ NH3 (g) + HCl (g)

State how the equation shows that the reaction is reversible.

How did you do?

6b
2 marks

Some ammonium chloride is heated gently in a test tube.

The diagram shows the test tube after it has been heated gently for a short time.

A test tube drawn at an angle, its mouth pointing up to the right and its rounded base at the lower left. A dark grey solid sits in the rounded base and a leader line labels it ammonium chloride. A pale grey solid coats the inside of the tube near its mouth and a leader line labels it X. A leader line from the empty middle section of the tube, between the two solids, is labelled Y.

Identify solid X and the two gases formed in region Y of the test tube.

Solid X ................................................................................................

Gases at Y ..................................................................................................

[2]

How did you do?

6c
3 marks

An experiment involving ammonium chloride can be used to show the process of diffusion.

The diagram shows the apparatus at the start of the experiment.

A long horizontal glass tube, stoppered at both ends. A plug of cotton wool sits just inside the left-hand end, labelled by a leader line as cotton wool soaked in concentrated ammonia solution. A second plug of cotton wool sits just inside the right-hand end, labelled by a leader line as cotton wool soaked in concentrated hydrochloric acid. Three positions along the empty middle of the tube are marked A, B and C from left to right, with A closest to the ammonia end and C closest to the hydrochloric acid end.

At the end of the experiment, a white solid forms in the test tube. Explain which position, A, B or C, shows where the white solid forms.

How did you do?

6d
1 mark

Which change of state occurs in the test tube during heating?

  • condensing

  • evaporating

  • melting

  • subliming

Choose your answer

7a
1 mark

Potassium permanganate is a purple solid that is soluble in water.

A crystal of potassium permanganate is placed in a beaker containing water.

After a short time, the crystal becomes smaller and the liquid at the bottom of the beaker becomes purple.

Which statement explains this observation?

  • the crystal condenses in the water

  • the crystal dissolves in the water

  • the crystal evaporates in the water

  • the crystal melts in the water

Choose your answer

7b
1 mark

The beaker is left until there is no further change in the appearance of the liquid.

Which statement describes the final appearance of the liquid?

  • all of the liquid is purple

  • none of the liquid is purple

  • only the bottom half of the liquid is purple

  • only the top half of the liquid is purple

Choose your answer

7c
1 mark

The formula of potassium permanganate is KMnO4.

How many different elements are there in potassium permanganate?

  • 3

  • 4

  • 6

  • 7

Choose your answer

7d
1 mark

The beaker is left until there is no further change in the appearance of the liquid.

Which process causes this change in appearance?

  • condensation

  • crystallisation

  • diffusion

  • evaporation

Choose your answer

1a
2 marks

Lead nitrate and potassium iodide react to form the insoluble solid lead iodide. Crystals of lead nitrate and potassium iodide are placed at opposite ends of a container of water. Solid lead iodide forms after several minutes. The diagram shows the container at the start and after several minutes.

Two line diagrams of the same shallow rectangular container of water, side by side. The left-hand diagram is labelled At the start: a horizontal line just below the rim shows the surface of the water, and two small black dots sit on the base of the container, one near the left-hand end labelled crystals of potassium iodide and one near the right-hand end labelled crystals of lead nitrate. The right-hand diagram is labelled After several minutes: the water surface line is unchanged, the two dots have gone, and a short vertical black mark stands on the base about two thirds of the way along from the left-hand end, labelled lead iodide.

Name the two processes that occur before the solid lead iodide forms.

How did you do?

1b
3 marks

Explain why solid lead iodide takes less time to form when the reaction is repeated using water at a higher temperature.

How did you do?

1c
2 marks

The formula for lead nitrate is Pb(NO3)2

i) Give the number of different elements in lead nitrate.

[1]

ii) Give the charge on the lead ion in Pb(NO3)2

[1]

How did you do?

1d
1 mark

Complete the chemical equation for the reaction between lead nitrate and potassium iodide. 

Pb(NO3)2 (aq) + .......... KI (aq) → PbI2 (s) + .......... KNO3 (aq)

How did you do?

2a
1 mark

The table gives the melting and boiling points of four pure substances, W, X, Y and Z.

Melting point in °C

Boiling point in °C

W

-7

60

X

660

2500

Y

180

1330

Z

115

445

Use data from the table to answer the questions.

Which substance is a gas at 100 °C?

  • W

  • X

  • Y

  • Z

Choose your answer

2b
1 mark

Use data from the table in part (a) to answer the question.

Which substance is a liquid for the largest range of temperature?

  • W

  • X

  • Y

  • Z

Choose your answer

2c
1 mark

Use data from the table in part (a) to answer the question.

Which substance is a liquid at 1000 °C and a gas at 2000 °C?

  • W

  • X

  • Y

  • Z

Choose your answer

2d
1 mark

Substance Y does not conduct electricity when solid but does conduct electricity when molten.

Give the type of bonding in substance Y.

How did you do?

2e
1 mark

Suggest how the melting point of a pure substance changes when an impurity is added.

How did you do?