Amounts of substance in equations

When iron rusts, iron(III) oxide forms.

State two conditions needed for iron to rust.

What is the name of the process used to coat iron with zinc?

What is the correct order of reactivity of these four metals?

Describe a test to show that a solution contains Fe³⁺ ions.

test

result

A sample of iron(III) oxide reacts with excess carbon monoxide.

This is the equation for the reaction.

Explain why this is a redox reaction.

Calculate the minimum mass of iron(III) oxide needed to produce a theoretical yield of 28 g of iron.

[for Fe₂O₃ M_r = 160]

The actual yield of iron from this sample is 21 g.

Calculate the percentage yield of iron.

Magnesium sulfate crystals have the formula MgSO₄.xH₂O

A student uses this apparatus to heat tube A and collect water of crystallisation in tube B.

The student records the mass of tube B at the start and every minute for 6 minutes.

The table gives the student’s results.

Give a reason why the student surrounds tube B with ice.

State how the student knows when all the water of crystallisation has been given off.

Describe a chemical test the student can use to show that the liquid in tube B contains water.

The decomposition of hydrated magnesium sulfate is shown in the equation.

At the end of the reaction, the mass of MgSO₄ remaining in the tube is 6.0 g.

Use this mass and the results in the table to calculate x in MgSO₄.xH₂O

[for MgSO₄, M_r = 120 for H₂O, M_r = 18]

This question is about the reactions of some compounds of lead.

Lead can be extracted from lead(II) sulfide, PbS, in two stages.

Stage 1 lead(II) sulfide is heated in air and reacts with oxygen to produce lead(II) oxide, PbO, and sulfur dioxide

Stage 2 lead(II) oxide is heated with carbon in a furnace

Write a chemical equation for the reaction in stage 1.

Give a reason why sulfur dioxide should not be released into the atmosphere.

This is the equation for stage 2.

A mass of 892 tonnes of lead(II) oxide is heated in a furnace with an excess of carbon.

Calculate the maximum mass, in tonnes, of carbon dioxide that could be released into the atmosphere.

[1 tonne = 110⁶g]

[for PbO, M_r = 223 for CO₂, M_r = 44]

The diagram shows the structures of lead(II) sulfide and sulfur dioxide.

Explain, in terms of bonding and structure, why lead(II) sulfide is a solid with a very high melting point at room temperature and why sulfur dioxide is a gas at room temperature.

lead(II) sulfide

sulfur dioxide

A different oxide of lead contains 90.7% by mass of lead and 9.3% by mass of oxygen.

Determine the empirical formula of this oxide of lead.

A teacher adds a small piece of lithium to water and collects the gas produced.

Give two observations when lithium is added to water.

The teacher adds a few drops of universal indicator to the solution at the end of the reaction.

Explain the final colour of the universal indicator.

This is the equation for the reaction between lithium and water.

The teacher collects 550 cm³ of hydrogen at rtp.

Calculate the mass, in grams, of lithium that the teacher added to the water.

[one mole of gas at rtp has a volume of 24 000 cm³]

[for lithium, A_r = 7]

[for carbon A_r = 12 for hydrogen, A_r = 1 for oxygen A_r = 16]

The teacher then adds a small piece of potassium to water.

Give one observation seen with potassium that is not seen with lithium.

Explain why potassium is more reactive than lithium.

Refer to atomic structure in your answer.

This question is about the metal tantalum, Ta.

Tantalum metal can be produced by heating tantalum chloride (TaCl₅) and hydrogen gas in a furnace.

The other product of the reaction is hydrogen chloride.

Complete the equation for the reaction.

As tantalum chloride is heated, the mass of solid in the furnace decreases leaving tantalum as the only solid product.

The table shows the mass of solid in the furnace at one-hour intervals.

State how the data in the table shows that the reaction is complete.

Use the data to show that the formula of tantalum chloride is TaCl₅

[for tantalum, A_r = 181 for chlorine, A_r = 35.5]

QUESTION 12 CONTINUES ON NEXT PAGE.

Another method of extracting tantalum is by reacting tantalum(V) oxide with carbon.

This is the equation for the reaction.

Explain why this is a redox reaction.

2000 mol of tantalum(V) oxide is heated with 500 000 g of carbon.

Show by calculation that the carbon is in excess.

[for carbon, A_r = 12]

Calculate the maximum mass, in grams, of tantalum that can be obtained from 2000 mol of tantalum(V) oxide.

[for tantalum, A_r = 181]

This question is about magnesium metal and its compounds.

The diagram represents the structure of magnesium.

Complete the diagram by adding the labels.

Explain why magnesium is malleable.

Magnesium burns in oxygen gas to form solid magnesium oxide.

Complete the chemical equation for the reaction by balancing the equation and adding the state symbols.

Give a reason why magnesium is oxidised in this reaction.

A student uses this method to make a solution of magnesium chloride.

Step 1 measure 25 cm³ of dilute hydrochloric acid into a beaker

Step 2 add magnesium powder a little at a time

Step 3 keep adding magnesium powder until it is in excess

Step 4 remove the excess magnesium powder by filtration

This is the equation for the reaction.

Give a reason why the student uses magnesium powder rather than magnesium ribbon.

Give a reason why the student adds an excess of magnesium in step 3.

Calculate the minimum mass of magnesium needed to react with 25.0 cm³ of 2.00 mol / dm³ hydrochloric acid.

[for Mg, A_r = 24]

A scientist reacts lead(II) nitrate solution with sodium bromide solution.

This is the equation for the reaction.

Pb(NO₃)₂(aq) + 2NaBr(aq) PbBr₂(s) + 2NaNO₃(aq)

Describe how the scientist could obtain a pure dry sample of lead(II) bromide (PbBr₂) from the reaction mixture.

The scientist reacts an excess of lead(II) nitrate solution with 25 cm³ of sodium bromide solution of concentration 2.0 mol/dm³.

Show that the amount of sodium bromide used is 0.050 mol.

Show that the maximum theoretical mass of lead(II) bromide is approximately 9 g.

[for PbBr₂ M_r = 367]

The scientist electrolyses molten lead(II) bromide using this apparatus.

Explain why lead(II) bromide needs to be molten rather than solid for electrolysis to occur.

The electrolyte is at a temperature of 400C.

Explain a suitable material for the electrodes.

Give the half‑equation that occurs at the negative electrode.

Bromine forms at the positive electrode.

This is the half‑equation for the reaction at the positive electrode.

State what is observed at the positive electrode.

State why the half‑equation represents an oxidation reaction.

A technician needs to identify the solution in an unlabelled bottle.

The technician knows that the solution contains one of these compounds.

• iron(II) bromide

• iron(II) chloride

• iron(III) bromide

• iron(III) chloride

Describe how the technician can use chemical tests to identify the compound.

When chlorine gas is passed over heated iron powder, iron(III) chloride forms.

This is the equation for the reaction.

0.060 mol of chlorine gas is passed over 2.8 g of iron powder.

Show by calculation that the iron powder is in excess.

When iron(III) chloride dissolves in water, an acidic solution forms.

Give the colour of litmus in this solution.

Give the formula of the ion that causes the solution to be acidic.

This method is used in an experiment to produce hydrated zinc nitrate crystals.

• pour 50 cm³ of dilute nitric acid into a beaker

• add a spatula of zinc powder to the acid

• add more zinc until it is in excess

• filter the mixture

• obtain crystals of zinc nitrate from the filtrate

State why the mixture is filtered.

Describe how a pure, dry sample of hydrated zinc nitrate crystals could be obtained from the filtrate.

This equation represents the formation of hydrated zinc nitrate in the experiment.

In another experiment, 9.75 g of zinc is completely reacted with nitric acid.

Show that the maximum possible mass of hydrated zinc nitrate crystals that could be formed is approximately 45 g.

[for Zn(NO₃)₂.6H₂O, M_r = 297]

The actual yield of hydrated zinc nitrate crystals is 36.4 g.

Calculate the percentage yield of hydrated zinc nitrate crystals.

This question is about the three halogens, bromine, chlorine and iodine.

Give the number of protons and the number of neutrons in an atom of iodine–127

number of protons

number of neutrons

A sample of bromine contains two isotopes.

• Br–79 with relative abundance 52.8 %

• Br–81 with relative abundance 47.2 %

Calculate the relative atomic mass (A_r) of this sample of bromine.

Give your answer to three significant figures.

Aluminium reacts with chlorine to form aluminium chloride.

This is the equation for the reaction.

Calculate the minimum mass of chlorine needed to form 26.7 g of aluminium chloride.

[for Cl₂, M_r = 71 for AlCl₃, M_r = 133.5]

A student mixes the following pairs of solutions.

Pair 1 bromine solution and potassium chloride solution

Pair 2 bromine solution and potassium iodide solution

Explain how the student can use the results of these experiments to show the order of reactivity of the three halogens, bromine, chlorine and iodine.

Include observations in your answer.

A teacher uses this apparatus to test the products of the combustion of liquid hydrocarbons.

Explain the change in appearance that occurs in the limewater.

The equation represents the complete combustion of an alkene.

C_nH_2n + oxygen carbon dioxide + nH₂O

Complete combustion of 0.0100 mol of the alkene produces 2.16 g of water.

Determine the molecular formula of this alkene.

[for H₂O, M_r = 18]

Give a reason why the mass of pure water that collects in the U-tube is less than 2.16 g.

Give a physical test to show that the water that collects in the U-tube is pure.

The teacher burns 30.0 g of heptane.

This is the equation for the complete combustion of heptane.

Calculate the minimum mass of oxygen needed for the complete combustion of 30.0 g of heptane.

[for C₇H₁₆, M_r = 100 for O₂, M_r = 32]

This question is about the oxides of some elements in Group 4 of the Periodic Table.

When 5.34 g of lead(II) carbonate are heated, lead(II) oxide and carbon dioxide are formed.

This is the equation for the reaction.

Give the name for this type of reaction.

Calculate the maximum mass of lead(II) oxide that can be formed from 5.34 g of lead(II) carbonate.

[for PbCO₃, M_r = 267 for PbO, M_r = 223]

The diagram shows apparatus used to heat lead(II) carbonate.

Complete the diagram to show what needs to be added to the apparatus to test that the gas released is carbon dioxide.

Give the result of the test.

Silicon dioxide (SiO₂) and carbon dioxide both contain covalent bonds.

Silicon dioxide is a solid with a high melting point. Carbon dioxide is a gas at room temperature.

Explain why silicon dioxide has a much higher melting point than carbon dioxide.

Refer to structure and bonding in your answer.

This question is about the reaction between magnesium and dilute nitric acid.

A student reacts dilute nitric acid with an excess of magnesium powder as a first step in the preparation of dry crystals of hydrated magnesium nitrate.

This is the equation for the reaction.

Explain why it is important that magnesium is in excess.

The student adds 0.75 g of magnesium to 0.025 mol of nitric acid.

Calculate the mass of magnesium, in grams, that remains at the end of the reaction.

[for magnesium, A_r = 24]

Describe how the student can obtain dry crystals of hydrated magnesium nitrate from the mixture at the end of the reaction.

The student repeats the experiment and records the volume of hydrogen gas collected.

The graph shows the student’s results.

Use the graph to calculate the rate of reaction, in cm³/ s, at t = 40 s.

Show your working on the graph.

A student uses this apparatus to investigate the reaction between magnesium and dilute hydrochloric acid.

The word equation for the reaction is

magnesium + hydrochloric acid magnesium chloride + hydrogen

Complete the chemical equation for this reaction.

Give the test for hydrogen.

The student uses 0.090 g of magnesium and 0.025 mol of hydrochloric acid.

Show by calculation that the hydrochloric acid is in excess.

The student measures the volume of hydrogen collected at regular intervals until the reaction stops.

The table shows the student’s results.

Plot the student’s results.

Draw a curve of best fit.

Determine the volume of hydrogen collected in the first 10 seconds.

Show on the graph how you obtained your answer.

Explain why the rate of reaction is greatest at the start of the reaction.

The student repeats the experiment at a temperature 5 °C higher than the original temperature.

All other conditions are kept the same.

On the grid, draw the curve you would expect the student to obtain.

Explain, in terms of particle collision theory, how increasing the temperature affects the rate of reaction.

This question is about the oxides of lead.

Yellow lead oxide (PbO) can be reacted with hydrogen to produce lead.

Complete the equation for the reaction by adding the missing state symbols.

What is the charge on the lead ion in PbO?

Explain why the reaction of yellow lead oxide with hydrogen is a redox reaction.

Describe a physical test to show that the water produced in this reaction is pure.

When red lead oxide (Pb₃O₄) is heated, yellow lead oxide forms.

The equation for the reaction is

A scientist heats a known mass of red lead oxide in a crucible in a fume cupboard.

The scientist leaves the crucible to cool, then records the total mass of the crucible and its contents.

Describe what the scientist should do next to make sure that all the red lead oxide has reacted.

The red lead oxide used in the reaction has a mass of 5.48 g.

Calculate the maximum mass of yellow lead oxide that could form.

[M_r of Pb₃O₄ = 685 M_r of PbO = 223]

A teacher uses this apparatus to reduce tungsten oxide.

This is the teacher’s method.

• record the mass of a weighing boat

• add tungsten oxide and record the mass again

• heat the weighing boat and tungsten oxide strongly for two minutes and then allow to cool

• record the mass of the weighing boat and its contents

Complete the equation by adding the state symbols.

Give an addition to the method to check that the tungsten oxide has been completely reduced.

The table shows the teacher’s results.

Use the teacher’s results to show that the empirical formula of tungsten oxide is WO₃

[for tungsten, A_r = 184 for oxygen, A_r = 16]

The teacher wears eye protection and a lab coat during the experiment.

Give one other safety precaution the teacher should take.

In industry, tungsten oxide is reduced on a large scale using hydrogen.

The percentage yield of tungsten is 73.5%

This is the equation for the reaction.

Calculate the mass, in tonnes, of tungsten that is produced when 2784 tonnes of tungsten oxide are reacted with an excess of hydrogen.

[1 tonne = 110⁶g]

[for tungsten, A_r = 184 for oxygen, A_r = 16]

mass of tungsten =_........ tonnes

A student uses this apparatus to heat crystals of hydrated zinc sulfate and collect the liquid produced.

Describe a chemical test to show that the colourless liquid contains water.

Describe a physical test to show the colourless liquid is pure water.

The equation for the decomposition of hydrated zinc sulfate is

The student records these masses.

mass of boiling tube = 41.64 g

mass of boiling tube + ZnSO₄·7H₂O = 54.46 g

Calculate the maximum volume, in cm³, of pure water that could be produced.

Give your answer to 1 decimal place.

[1.00 cm³ of pure water has a mass of 1.00 g]

[M_r of ZnSO₄·7H₂O = 287 M_r of H₂O = 18]

In an experiment using a different mass of ZnSO₄·7H₂O the maximum volume of pure water that could be produced is 8.5 cm³.

The student collected the pure water and calculated the percentage yield to be 20.3 %.

Calculate the volume, in cm³, of pure water collected.

Explain an improvement to the apparatus that would increase the percentage yield of pure water.

Metals are found in the Earth’s crust either as uncombined elements or in metal compounds in rocks.

The method of extraction of a metal is related to its position in the reactivity series.

The table shows the positions of some metals and carbon in the reactivity series.

State the name given to rocks that contain metal compounds used in the extraction of metals.

Name a metal that is found as an uncombined element in the Earth’s crust.

Carbon extraction and electrolysis are two methods of obtaining a metal from a compound.

Explain, without giving practical details, which method is most suitable to obtain calcium from calcium chloride.

Explain, without giving practical details, which method is most suitable to obtain lead from lead oxide.

Explain, using a labelled diagram, why lead metal is malleable.

Aluminium is extracted from aluminium oxide.

The overall equation for the process is

Calculate the maximum mass, in grams, of aluminium that could be obtained from 1.275 kg of aluminium oxide.

Organic compounds can exist as isomers.

Explain what is meant by the term isomers.

Organic compound Q reacts with bromine, without the presence of ultraviolet radiation, to form the compound C₄H₈Br₂

Draw the displayed formulae of two isomers of Q.

An acrylic polymer can be formed from molecules with this structure.

A student describes the molecule as an unsaturated hydrocarbon.

Explain whether this is a correct description.

Name the type of polymerisation that occurs in the formation of the polymer.

Complete the equation for the polymerisation reaction.

Octane is a compound in petrol.

The equation for the complete combustion of octane is

The fuel tank of a car contains 50.0 dm³ of octane.

Calculate the mass, in kg, of carbon dioxide formed if all the octane in the fuel tank undergoes complete combustion.

[mass of 1 dm³ of octane = 700 g]

State an environmental problem caused by carbon dioxide.

This question is about the insoluble salt silver chloride (AgC l).

Silver chloride can be made by the reaction between copper(II) chloride and silver nitrate.

Describe how a student could prepare a pure, dry sample of silver chloride starting with copper(II) chloride solution and silver nitrate solution.

A student investigates the quantity of silver chloride produced when different volumes of silver nitrate solution are added to copper(II) chloride solution.

This is the student’s method. pour 5.0 cm³ of copper(II) chloride solution into a test tube add 1.0 cm³ of silver nitrate solution to the test tube

allow the silver chloride precipitate to settle

measure the height of the precipitate

The student repeats the method using different volumes of silver nitrate solution.

The table shows the student’s results.

Plot the student’s results.

Draw two straight lines of best fit, ignoring the anomalous result.

Volume of silver nitrate added in cm³

Suggest a mistake the student made to cause the anomalous result.

Give a reason why the last three heights are the same.

The equation for the reaction between copper(II) chloride and silver nitrate is

CuCl₂(aq) + 2AgNO₃(aq) 2AgCl(s) + Cu(NO₃)₂(aq)

A student measures 25.0 cm³ of 0.500 mol/dm³ copper(II) chloride solution and reacts it with silver nitrate solution.

Name a piece of apparatus suitable for measuring 25.0 cm³ of copper(II) chloride solution.

Calculate the maximum mass, in grams, of silver chloride that could be produced.

[M_r of AgCl = 143.5]

In an experiment using different solutions, the mass of silver chloride produced is 0.744 g.

The maximum mass of silver chloride that could be produced is 0.850 g.

Calculate the percentage yield.

Sodium hydroxide dissolves in water, forming a strongly alkaline solution.

Ammonia dissolves in water, forming a slightly less alkaline solution.

Identify the ion that makes the sodium hydroxide solution alkaline.

What is a possible pH of ammonia solution?

When ammonia solution reacts with sulfuric acid, a neutralisation reaction occurs and ammonium sulfate forms.

How does the sulfuric acid act in this reaction?

The diagram shows a beaker containing some ammonia solution and a few drops of phenolphthalein indicator.

Dilute sulfuric acid is added to the beaker until it is in excess.

What are the colours of the phenolphthalein indicator before and after adding excess sulfuric acid?

Ammonium sulfate is used by gardeners as a fertiliser because it contains nitrogen.

Explain why the chemical formula of ammonium sulfate is (NH₄)₂SO₄

Refer to the charges on the ions in your answer.

Calculate the relative formula mass of ammonium sulfate, (NH₄)₂SO₄

Calculate the mass, in grams, of nitrogen in 1.0 kg of ammonium sulfate.

Sodium hydrogencarbonate (NaHCO₃) is also known as baking soda.

Baking soda can be used to make cakes increase in size in an oven.

This is the equation for the reaction that takes place when baking soda is heated.

What type of reaction is this?

Suggest why the reaction makes the cakes increase in size.

A student uses this apparatus to investigate the reaction that takes place when sodium hydrogencarbonate is heated.

This is the student’s method.

● weigh a crucible and record the mass

● add some sodium hydrogencarbonate to the crucible, reweigh it and record the mass

● heat the crucible and contents for five minutes, then allow to cool before weighing and recording the mass

● heat the crucible and contents again for a further three minutes, then allow to cool before weighing and recording the mass

Give a reason why the crucible and contents are heated for a further three minutes.

The student considered using a lid on the crucible in the experiment.

Suggest an advantage and a disadvantage of using a lid on the crucible.

The table shows some of the student’s results.

Calculate the mass of sodium hydrogencarbonate that the student uses.

Using this equation, calculate the maximum mass of sodium carbonate (Na₂CO₃) that could form in the student’s reaction.

[M_r of NaHCO₃ = 84 M_r of Na₂CO₃ = 106]

In a second experiment, the student uses a larger mass of sodium hydrogencarbonate.

She calculates that she should obtain 4.8 g of sodium carbonate.

She actually obtains 4.2 g of sodium carbonate.

Calculate the percentage yield from the student’s experiment.

Other than spillages, suggest a possible reason why the student’s actual yield is less than expected.

This question is about reactions involving gases.

Potassium carbonate reacts with dilute hydrochloric acid to produce carbon dioxide gas.

The equation for the reaction is

Calculate the volume, in cm³, of carbon dioxide gas produced when 6.9 g of potassium carbonate reacts with excess dilute hydrochloric acid.

[M_r of K₂CO₃ = 138]

[molar volume of CO₂ at rtp = 24 dm³]

This reaction involving gases is in dynamic equilibrium at a temperature of 225C.

Predict the effect on the yield of CO(g) at equilibrium when the temperature is increased without changing the pressure.

Give a reason for your answer.

Predict the effect on the yield of CO(g) at equilibrium when the pressure is increased without changing the temperature.

Give a reason for your answer.

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

Name one other reactant needed for this reaction to occur.

Which colour change occurs during this reaction?

When ethanol is burned in air, complete combustion can occur.

The equation for this reaction is

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

H H

H H

The table gives the bond energies for these bonds.

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

energy needed_........

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

energy released_........

Calculate the molar enthalpy change (Δ H) in kJ/mol, for the complete combustion of ethanol.

Include a sign in your answer.

ΔH =_........ kJ/mol

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

The equation for the reaction is

Give the name of the ester that forms.

Draw the displayed formula for this ester.

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

Give two characteristics of a reaction at dynamic equilibrium.

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

The equation for the reaction is

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]

Complete the chemical equation for the reaction in stage 1.

Give the meaning of the symbol

State the purpose of the platinum catalyst.

Give a chemical equation for the reaction of nitrogen monoxide and oxygen in stage 2.

The equation for the reaction in stage 3 is

Calculate the maximum mass, in tonnes, of nitric acid that could be produced in this reaction from 11.5 tonnes of nitrogen dioxide.

mass of nitric acid =_........ tonnes

Suggest what use can be made of the nitrogen monoxide gas formed in stage 3.

When copper(II) oxide reacts with dilute nitric acid, copper(II) nitrate is produced.

The equation for the reaction is

0.200 mol of nitric acid reacts with excess copper(II) oxide.

A mass of 15.3 g of copper(II) nitrate is produced.

Calculate the percentage yield of copper(II) nitrate.

[M_r of copper(II) nitrate = 187.5]

This question is about the reduction of metal oxides.

Solid oxides of copper can be reduced by reacting them with methane gas.

Complete the equation for the reaction between copper(II) oxide and methane.

Include state symbols.

_........ CuO(_........ ) +_........ CH₄(_........ ) _........ Cu(_........ ) +_........ CO₂(_........ ) +_........ H₂O(_........

A teacher uses this apparatus to demonstrate the reaction between a different oxide of copper and methane.

The teacher heats the oxide of copper until the reaction is complete.

The table shows the teacher’s results.

Use the teacher’s results to show that the empirical formula of this oxide of copper is Cu₂O

The teacher wears safety glasses and a lab coat during the demonstration.

Give one other safety precaution that she should take.

Iron forms when iron(III) oxide is heated with carbon.

The equation for the reaction is

State how the equation shows that iron(III) oxide is reduced.

State why carbon monoxide should not be released into the atmosphere.

Calculate the maximum mass, in tonnes, of iron that can be produced when 30.0 tonnes of iron(III) oxide are reacted with an excess of carbon.

[1 tonne = 1.0 × 10⁶ g]

A mixture of 25 000 mol of iron(III) oxide and 840 000 g of carbon is heated.

Use this equation to show that the iron(III) oxide is in excess.

Solutions of silver nitrate and potassium chloride react together to make the insoluble salt, silver chloride.

A student uses this method to prepare a sample of silver chloride.

Step 1 add 25 cm³ of silver nitrate solution to a conical flask

Step 2 add potassium chloride solution to the flask

Step 3 filter off the silver chloride

What term is used for this reaction?

Give two more steps that will produce a pure, dry sample of silver chloride.

Acidified silver nitrate solution is used to test for chloride ions.

Give a reason why hydrochloric acid is not used to acidify silver nitrate solution.

The chemical equation for the reaction between solutions of silver nitrate and potassium chloride is

AgNO₃(aq) + KCl(aq) AgCl(s) + KNO₃(aq)

A student adds an excess of potassium chloride solution to 25.0 cm³ of 0.100 mol/dm³ silver nitrate solution.

Calculate the maximum mass of silver chloride, in grams, that can be produced.

[M_r of AgCl = 143.5]

This question is about some Group 2 elements and their compounds.

Calcium reacts with water to produce calcium hydroxide and hydrogen gas.

Give the word equation for this reaction.

State two observations that would be made during this reaction.

Describe how a pure, dry sample of the insoluble salt, barium sulfate, could be made from the two solids sodium sulfate and barium chloride.

Give an ionic equation for the reaction that occurs.

Include state symbols in your equation.

When magnesium nitrate is heated, magnesium oxide, nitrogen dioxide and oxygen form.

The equation for the reaction is

What is the name for this type of reaction?

Calculate the total volume, in dm³, of gas produced at rtp when 7.7 g of magnesium nitrate completely reacts.

[Assume that the molar volume of a gas at rtp is 24 dm³]

[M_r of Mg(NO₃)₂ = 148]

Give your answer to two significant figures.

Hydrogen gas can be produced by reacting a mixture of methane and steam in the presence of a nickel catalyst.

The reaction conditions are a temperature of 700C and a pressure of 5 atmospheres.

The equation for the reaction is

What does the symbol represent?

The mixture of methane and steam is heated to a temperature greater than 700 °C but the pressure is kept at 5 atmospheres.

Predict the effect of this change on the yield of hydrogen at equilibrium, giving a reason for your answer.

The mixture of methane and steam is kept at the same temperature of 700 °C but the pressure is increased to more than 5 atmospheres.

Predict the effect of this change on the yield of hydrogen at equilibrium, giving a reason for your answer.

Calculate the volume, in dm³, of hydrogen gas at rtp that is produced when 10 tonnes of methane gas completely react with steam.

[molar volume of hydrogen at rtp is 24 dm³]

Give your answer in standard form.