The three states of matter

Which state of matter is shown in the diagram?

B A liquid

C A solid

D A solution

The table shows the boiling points of four substances made from simple molecules.

Which substance has the weakest intermolecular forces?

Sodium chloride is an ionic compound.

Sodium chloride is made from sodium ions, Na +, and chloride ions, C l –. (a)

Fig. 13.1 shows a model for the ionic lattice of sodium chloride.

Complete by writing in the missing sodium ions, Na +, and chloride ions, C l –. Fig. 13.1

Fig. 13.1

What is the formula of sodium chloride?

Sodium chloride can be split up into its elements using electrolysis.

During electrolysis, sodium chloride must be heated until it is a liquid.

The table shows the melting point and boiling point of sodium chloride.

Suggest a temperature that sodium chloride should be heated to so it is a liquid.

Fig. 13.2 shows a diagram for the electrolysis of molten sodium chloride.

Fig. 13.2

What is the name of the piece of equipment, X ?

Name the gas produced at the anode.

A student thinks that the electrodes (anode and cathode) should be inert and made from graphite.

Complete the sentences to explain why the student is correct.

Graphite is reactive / unreactive. It is an electrical conductor / electrical insulator.

Sodium chloride contains 39% sodium.

Calculate the mass of sodium that is produced from the electrolysis of 160 kg of sodium chloride.

Give your answer to 2 significant figures.

* Fig. 13.3 shows the dot and cross diagram for sodium chloride.

Fig. 13.3

Sodium atom Chlorine atom Sodium ion Chloride ion

Explain how sodium and chlorine atoms form sodium and chloride ions.

Use information:

• from Fig. 13.3

• your knowledge of chemical bonding

• ideas about the electron arrangement in the atoms and ions.

This question is about elements in Group 1 and Group 7 of the Periodic Table.

Sodium is below lithium in Group 1.

Table 12.1 describes the observations when small pieces of lithium and sodium are placed in water.

Table 12.1

Describe how these observations show how the reactivity of the elements increases going down Group 1.

Potassium is below sodium in Group 1.

Describe one observation when a small piece of potassium is placed in water.

Use information from Table 12.1.

When sodium reacts with water, it forms sodium hydroxide and hydrogen.

Complete the word equation for the reaction of potassium with water.

The equation for sodium, Na, reacting with a Group 7 element, X, is:

Sodium is a solid at room temperature.

Complete the equation by writing in the missing state symbol for sodium.

State the name of element X.

A more reactive Group 7 element displaces a less reactive Group 7 element from a solution of one of its salts.

Chlorine reacts with potassium bromide as chlorine is more reactive than bromine.

Bromine reacts with potassium iodide as bromine is more reactive than iodine.

Iodine does not react with potassium chloride as iodine is less reactive than chlorine.

Table 12.2 shows the results of mixing three Group 7 elements and solutions of their salts.

Table 12.2

Key ✓ = reaction ✗ = no reaction

Complete Table 12.2 by putting a tick (✓) or cross (✗) in the three answer spaces.

The diagram shows a chemical reaction.

During the reaction the mass on the balance decreases.

Which state symbol describes the product that causes the mass to decrease?

A aq

B g

C l

D s

The particle model is used to describe changes of state.

Which statement about the particle model is correct ?

A It takes into account the forces between particles.

B It takes into account the size of the particles.

C It takes into account the space between the particles.

D It represents the particles as inelastic spheres.

Atoms are made from the sub-atomic particles protons, neutrons and electrons.

Table 12.1 shows the relative mass and relative charge of the three sub-atomic particles.

Complete Table 12.1 by writing the name of a sub-atomic particle in each space.

Table 12.1

An atom of phosphorus has an atomic number of 15 and a mass number of 31.

Calculate the number of protons, neutrons and electrons in this atom of phosphorus.

Phosphorus reacts with oxygen to form an oxide called phosphorus trioxide.

Phosphorus trioxide has the molecular formula P₄O₆.

What is the empirical formula of phosphorus trioxide?

Tick (✓) one box.

Complete the balanced symbol equation for the reaction of phosphorus trioxide with water.

Table 12.2 shows the melting point and boiling point of phosphorus trioxide.

Table 12.2

In the box draw the particle arrangement for phosphorus trioxide at 100 °C.

The properties of materials depend on their structure and bonding.

The table shows some information about four materials.

Draw four lines to connect each material with its correct structure.

Ethene, C₂H₄, has this structure.

Complete the dot and cross diagram for a molecule of ethene.

Only show the outer shell electrons.

Explain why ethene has a low boiling point.

Use ideas about structure and bonding.

The equation shows how ethene can be produced.

The table shows some bond energies.

Calculate the total energy transferred to break all the bonds in the reactant.

Energy transferred to break all the bonds =........ kJ / mol

Calculate the total energy transferred to make all the bonds in the products.

Energy transferred when all the bonds are made =........ kJ / mol

Use your answers to parts (i) and (ii) to calculate the energy change for the reaction.

Energy change =........ kJ / mol

Sodium hydroxide, NaOH, and calcium hydroxide, Ca(OH)₂, are ionic compounds that dissolve in water to form alkaline solutions.

Why are solutions of sodium hydroxide and calcium hydroxide called alkalis?

Explain why the formula of sodium hydroxide is NaOH but the formula of calcium hydroxide is Ca(OH)₂.

The electrolysis of a sodium hydroxide solution produces hydrogen at the cathode rather than sodium.

Explain why.

When carbon dioxide is bubbled through a calcium hydroxide solution it turns cloudy white.

This is the equation for the reaction.

Which chemical in the equation turns the solution cloudy white?

What is the alternative name for the calcium hydroxide solution?

The calcium hydroxide solution contains 0.038 g of calcium hydroxide.

Calculate the maximum mass of carbon dioxide that can react with the calcium hydroxide solution.

Give your answer to 2 significant figures.

Relative atomic mass (A_r): H = 1.0 C = 12.0 O = 16.0 Ca = 40.1

When iron reacts with dilute hydrochloric acid, bubbles of hydrogen are produced.

Which state symbol describes these bubbles?

A aq

B g

C l

D s

The diagram represents the particle model for a change in the arrangement of some particles.

Which row describes this change?

A student investigates mixtures of salt and water.

The student has a solution of salt dissolved in water. The diagram shows how they separate pure water from the solution.

What name is given to this method of separation? Tick (✓) one box.

The particle diagrams represent changes of state.

Which diagram represents what happens in the boiling tube?

Tick (✓) one box.

After several minutes the glass tube becomes hot, and no more water is collected in the test tube.

Give one reason why the glass tube becomes hot.

The student wants the experiment to work for longer.

What other piece of equipment can they use instead of the glass tube?

The student also investigates how adding salt to ice changes the melting point of the ice.

The table shows their results.

The student draws a bar chart of the results.

Draw a bar on the bar chart for the results when 4 g of salt are added to the ice.

Describe how changing the mass of salt changes the melting point.

The student thinks the results show that pure ice will have a melting point of 0 C.

Explain why the student is correct.

Crude oil is a source of useful chemicals called hydrocarbons.

Complete the sentence about crude oil.

Crude oil is a compound / feedstock / renewable resource used by the petrochemical industry.

The diagram shows the fractionating column used in the fractional distillation of crude oil.

Which state symbol describes the crude oil as it enters the fractionating column?

Tick (✓) one box.

Write an X on the fractionating column where it is coolest.

The table shows the boiling point of four hydrocarbons.

Which of the hydrocarbons P, Q, R or S is produced nearest to the top of the fractionating column?

Which of the hydrocarbons P, Q, R or S has the largest molecules?

Large hydrocarbons can be made more useful by cracking.

The equation shows the cracking of hydrocarbon X.

What is the formula of hydrocarbon X ?

Which homologous series of hydrocarbons does C₆H₁₄ belong to?

The hydrocarbon C₂H₄ belongs to a different homologous series.

Suggest the general formula of the homologous series that contains C₂H₄.

Tick one (✓) box.

The diagram represents the particle model for a change in the arrangement of some particles.

Which row describes this change?

This is the equation for the reaction between copper carbonate and dilute hydrochloric acid:

What is the state symbol for CuCl₂?

A aq

B g

C l

D s

Describe what happens when solid potassium bromide is heated up until it melts into a liquid.

Use ideas about the particle model.

Explain why potassium bromide must be molten for electrolysis to happen.

State the product made at the cathode and write the half equation for the reaction.

The electrolysis is repeated with a solution of potassium bromide.

A student thinks that the same product will be formed at the cathode.

Explain why the student is incorrect.

Name of the different product formed........

Lead has a melting point of 328 °C. Mercury has a melting point of –39 °C.

Which row describes the state of lead and mercury at 100 °C?

Fig. 11.1 shows the particle model for an element.

Fig. 11.1

Solid Liquid Gas

Complete Fig. 11.1 by drawing in the particles of the element when it is a gas.

Describe how the particles of the element move in a solid.

Name the change of state labelled X on Fig. 11.1.

The table shows the state of the element chlorine at three different temperatures.

Use the information in the table to estimate the melting point of chlorine.

Tick (✓) one box.

A particle of chlorine has the formula Cl₂.

Fig. 11.2 shows some of the outer electrons in a particle of chlorine.

Fig. 11.2

Complete Fig. 11.2 by drawing in the missing outer electrons.

Complete the sentences about the bonding in a particle of chlorine.

The particles of chlorine are called isotopes / molecules / polymers.

The atoms of chlorine are joined together by a covalent / ionic / metallic bond.

Which test is used to identify chlorine?

Tick (✓) one box.

The equation for the reaction is

Complete the balanced symbol equation for the reaction by writing in the missing state

symbol for copper chloride solution.

The student thinks that the experiment shows that electrode X is the cathode.

Explain why the student is correct. Use the diagram.

Use the data in the table to show that the mass of copper produced doubles as the current doubles.

Plot a graph of the results on the grid.

Draw a line of best fit.

The student thinks that the result for the mass of copper produced at 3 A is incorrect

Explain how the student knows this result is incorrect.

Use your graph to predict the mass of copper that should have been produced at 3 A.

The table shows the boiling points of three Group 1 elements.

How many of these elements are gases at 700 °C?

A 0

B 1

C 2

D 3

The student has difficulty filling the measuring cylinder with water.

They change the measuring cylinder for a different piece of apparatus which allows them to measure the volume of hydrogen more accurately.

Name the piece of apparatus they use and complete the diagram below to show this apparatus.

Name of piece of apparatus........

Complete the balanced symbol equation for the reaction.

The student repeats the experiment. The only difference is they use a higher concentration of acid.

Draw a line on the graph to show the results of this experiment.

If the experiment is repeated at a higher temperature, the rate of reaction increases.

Explain why. Use ideas about particles and collisions.

Which row lists the material that has the weakest intermolecular forces?

The diagram shows the particle model for the condensation of a gas into a liquid.

Which is a limitation of the particle model?

A It does not show the arrangement of the particles.

B It does not show the movement of the particles.

C It does not take account of the energy of the particles.

D It does not take account of the forces between particles.

The student has difficulty filling the measuring cylinder with water.

They change the measuring cylinder for a different piece of apparatus which allows them to measure the volume of hydrogen more accurately.

Name the piece of apparatus they use and complete the diagram below to show this apparatus.

Name of piece of apparatus........

Complete the balanced symbol equation for the reaction.

The student repeats the experiment. The only difference is they use a higher concentration of acid.

Draw a line on the graph to show the results of this experiment.

If the experiment is repeated at a higher temperature, the rate of reaction increases.

Explain why. Use ideas about particles and collisions.

Complete each sentence to describe the formation of nitrogen dioxide.

Use the words or phrases in the list.

The molecules of nitrogen and oxygen........

The atoms then........ to form nitrogen dioxide.

This is called a........

The equation shows the formation of nitrogen dioxide.

Complete the balanced symbol equation for the reaction.

Use Fig. 11.1.

The table shows the melting point and boiling point of pure nitrogen dioxide.

Which state symbol shows the physical state of nitrogen dioxide at –2 °C?

Tick (✓) one box.

A scientist measures the melting point of a sample of nitrogen dioxide.

The result shows that the sample of nitrogen dioxide is impure.

Which temperature could be the melting point of the impure nitrogen dioxide?

Tick (✓) one box.

A molecule of nitrogen dioxide has the formula NO₂.

Calculate the relative formula mass for nitrogen dioxide.

Relative atomic mass (A_r): N = 14.0 O = 16.0

Nitrogen dioxide is made from the reaction of nitrogen with oxygen.

Fig. 11.2 shows the bonding in a molecule of oxygen, O₂.

Fig. 11.2

Fig. 11.3 shows an incomplete dot and cross diagram for oxygen.

Fig. 11.3

Complete Fig. 11.3 to show the arrangement of the electrons in a molecule of oxygen.

This question is about the Group 7 elements.

Table 16.1 shows some information about the Group 7 elements.

Table 16.1

Complete the table by predicting the appearance of astatine at room temperature.

Write your answer in the box in Table 16.1.

The sizes of the molecules are measured in picometres (pm).

What is the size of a fluorine molecule in metres (m)?

Tick (✓) one box.

Use Table 16.1 to complete the x axis and plot a line graph of the boiling points of fluorine, chlorine, iodine and astatine against the size of their molecules.

Draw a line of best fit.

Use your graph to predict the boiling point of bromine.

Table 16.1 is repeated below.

Table 16.1

A student thinks that fluorine molecules have the weakest intermolecular forces.

Give two reasons why they are correct.

Use data from Table 16.1.

Describe one similarity and one difference in the arrangement of electrons in atoms of fluorine and chlorine.

Similarity........

Difference........

13* Hydrogen can form compounds with the Group 7 elements. These compounds are simple covalent molecules.

For example,

When simple covalent molecules are heated, they thermally decompose back into their elements.

For example,

Tables 13.1 and 13.2 show information about the compounds formed from hydrogen and some Group 7 elements.

Table 13.1

Table 13.2

Describe the trends in the properties of the compounds in Table 13.1.

Explain these trends using information from Table 13.2 and ideas about the structure and bonding of simple covalent molecules.

Calcium is a metal found in Group 2 of the Periodic Table.

Draw the arrangement of electrons in an atom of calcium.

Calcium is a metal which can conduct electricity.

Describe the structure and bonding in a metal and explain why metals can conduct electricity.

You can include a diagram in your answer.

Calcium reacts with water to form a solution of calcium hydroxide, Ca(OH)₂, and hydrogen.

Write the balanced symbol equation for the reaction of calcium with water.

Include state symbols in your equation.

A solution of calcium hydroxide is also called limewater.

Name the gas limewater is used as a test for.

Calculate the number of moles in 1.88 g of calcium hydroxide.

Give your answer to 2 significant figures.

Relative atomic mass (A_r): H = 1.0 O = 16.0 Ca = 40.1

Use your answer to part (d)(i) to calculate the concentration of calcium hydroxide in the solution formed.

Give your answer in mol / dm³.

Concentration of solution =........ mol / dm³

A student adds an excess of dilute hydrochloric acid, HC l, to a solution of calcium hydroxide, Ca(OH)₂.

Write the balanced ionic equation for the reaction of dilute hydrochloric acid and a solution of calcium hydroxide.

Describe and explain how the pH of the solution of calcium hydroxide changes as the dilute hydrochloric acid is added until it is in excess.

This question is about the Group 7 elements.

Table 11.1 shows some information about the Group 7 elements.

Table 11.1

Complete the table by predicting the appearance of astatine at room temperature.

Write your answer in the box in Table 11.1.

The sizes of the molecules are measured in picometres (pm).

What is the size of a fluorine molecule in metres (m)?

Tick (✓) one box.

Which element has a molecule that is closest to twice the size of a molecule of fluorine?

Tick (✓) one box.

Use Table 11.1 to complete the x axis and plot a line graph of the boiling points of fluorine, chlorine, iodine and astatine against the size of their molecules.

Draw a line of best fit.

Use your graph to predict the boiling point of bromine.

Table 11.1 is repeated below.

Table 11.1

A student thinks that fluorine molecules have the weakest intermolecular forces.

Give two reasons why they are correct.

Use data from Table 11.1.

Describe one similarity and one difference in the arrangement of electrons in atoms of fluorine and chlorine.

A heating curve shows how the temperature of a substance changes as it is heated.

Fig. 14.1 shows the heating curve for ice.

Look at the sentences, A – D. They describe sections 1, 2, 3 and 4 of the heating curve in Fig. 14.1.

A Heat energy is used to break the forces between the particles.

B Heat energy is used to loosen the forces between the particles.

C Heat energy is used to make the particles move past each other more.

D Heat energy is used to make the particles vibrate faster.

Match the sentences A, B, C or D to the parts of the heating curve labelled 1, 2, 3 and 4 putting the correct letter in each box.

A student wants to produce the heating curve for ice.

Fig. 14.2 shows the equipment the student uses.

The student slowly heats up the ice and measures the temperature every minute.

The student found they could not produce part X of the heating curve in Fig. 14.1.

Explain why.

The table shows the melting points of four different substances, A – D.

State the letter, A, B, C or D, of one pure substance in the table.

State a reason for your answer to (c)(i) using information from the table.

Complete the balanced symbol equation for the reaction of sodium and chlorine to make sodium chloride.

Sodium chloride has a high melting point.

Explain why.

Use ideas about the structure and bonding in sodium chloride in your answer.

Write in the table the state symbol for the solution of sodium chloride.

Tick (✓) one box in each column of the table to show if solid sodium chloride and a

solution of sodium chloride conduct electricity.

Complete the table by writing in the explanation for the student’s results.

Use ideas about the structure and bonding in sodium chloride in your answer.

The table shows some information about the Group 7 elements.

How many Group 7 elements are liquid at −40 °C?

A 0

B 1

C 2

D 3

Crude oil is a mixture of alkanes which can be separated into different fractions.

The different fractions have a range of different boiling points.

The diagram shows the process of fractional distillation.

Explain how fractional distillation separates the crude oil into fractions.

Icosane, C₂₀H₄₂, is an alkane found in one of the fractions.

It has a boiling point of 343 °C.

Which fraction, A, B, C, D, E or F, contains icosane?

Icosane is converted into more useful products by cracking.

State the two conditions used for cracking.

Many different products can form when cracking icosane.

In one reaction, a molecule of icosane (C₂₀H₄₂) forms a molecule of hydrogen, H₂, and one other product.

Write the balanced symbol equation for this reaction.

* Fraction A contains the alkanes methane, ethane, propane and butane.

Table 14.1 shows some information about these four alkanes.

Describe and explain the similarities and differences in the boiling point of these four alkanes.

Use information in Table 14.1 and your knowledge of structure and bonding in your answer.

Copper can be produced from a copper(II) sulfate solution by electrolysis.

A student investigates how the mass of copper produced changes with the size of the current used during the electrolysis. The student varies the current used during electrolysis and investigates the mass of copper produced at the cathode.

The diagram shows the apparatus they use.

Copper(II) sulfate solution

The student:

• Measures the mass of the dry cathode at the start of the experiment.

• Switches the power pack on for 10 minutes.

• Removes the cathode and washes it with water.

• Dries the cathode.

• Measures the mass of the cathode again.

• Calculates the mass of copper formed at the cathode.

The student repeats the experiment at different currents.

They plot a graph of their results.

The copper(II) sulfate solution contains copper ions, Cu²⁺. (a)

Write the balanced half equation for the formation of copper at the cathode.

Include state symbols in the equation.

Look at the graph.

The student decides that the result for the mass of copper formed at the cathode at 2 A is incorrect.

Give a reason for this result.

Has the student drawn the correct line of best fit?

Give a reason for your answer.

Explain how repeating the experiment could improve the accuracy of the results.

Use the graph to calculate the mass of copper produced by a current of 15 A.

Give your answer to 1 significant figure.

The particle model used to describe solids, liquids and gases has some limitations.

Which of the following is not a limitation of the particle model?

A The forces of attraction between particles.

B The number of the particles.

C The size of the particles.

D The space between the particles.

People use perfumes to make them smell nice.

Look at the table. It shows the percentages of the different ingredients in a perfume.

What is the name given to a mixture, such as perfume, where the ingredients are combined in exact amounts?

A bottle contains 25 g of the perfume.

Calculate the mass of water in 25 g of the perfume.

Suggest why the alcohol evaporates very quickly.

Phosphoric acid, H₃PO₄, is a strong acid.

A student investigates how the pH of a solution of dilute phosphoric acid changes when a solution of calcium hydroxide is slowly added to it from a burette.

The student then calculates the concentration of hydrogen ions as the pH changes.

Table 16.1 shows the results of her experiment.

Explain why phosphoric acid is described as a strong acid.

Explain why the solution of phosphoric acid used is described as dilute.

Complete the balanced symbol equation for the reaction between phosphoric acid and calcium hydroxide.

The table shows the melting and boiling points of bromine.

Which change of state happens when bromine is cooled from 65 °C to −5 °C?

A Condensation

B Evaporation

C Freezing

D Melting

Table 14.1 shows the melting points of some of the Group 1 metals.

Plot the data in Table 14.1 on the grid in Fig. 14.1.

Draw a line of best fit.

Describe the relationship between the atomic number of the Group 1 metals and their melting points shown in Fig. 14.1.

Describe the metallic bonding in sodium.

Use information from Fig. 14.2 in your answer.

Look at the melting points of sodium and lithium in Table 14.1.

Suggest a reason for the difference in their melting points.

The alkanes in crude oil can be separated by fractional distillation.

This is because they have different boiling points.

The table shows the boiling points of hexane and octane.

Hexane molecules are smaller than octane molecules.

Explain the difference in the boiling points of hexane and octane.

A teacher checks the boiling point of hexane.

The diagram shows his experiment.

The teacher slowly heats up the water until hexane boils.

He records the temperature at the boiling point of hexane.

A student thinks that this method can be used to determine the boiling point of hexane but not the boiling point of octane.

Explain why the student is correct.

Which of these processes is an example of a physical change?

A Combustion

B Freezing

C Neutralisation

D Oxidation

The equation shows the reaction of sodium with water.

Sodium hydroxide and hydrogen are made.

Two of the state symbols are missing.

What are the missing state symbols?

A (l), (l)

B (s), (g)

C (aq), (g)

D (l), (g)

What is the melting point of substance X ?

What is the state of matter of substance X at 70 °C?

Tick (✓) one box.

In which state of matter do the particles of X have the most energy?

Tick (✓) one box.

Another substance, Y, is heated.

Substance Y is an ionic compound.

Substance Y has a much higher melting point than substance X.

Substance X is a simple covalent compound.

Which substance, X or Y, is made up of molecules ?

Tick (✓) one box.

Explain your answer.

Explain the difference between the melting points of substances X and Y.

Use ideas about the forces between the particles.

The particle model does not take into account certain information about the particles.

Which of the following does the particle model take into account?

A The size of the particles.

B The space between the particles.

C The number of particles.

D The force of attraction between the particles.