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Topic 2: Inorganic Chemistry
Subtopic 2a: Group 1 (alkali metals) – lithium, sodium and potassium
1) This question is about some of the alkali metals and their compounds.
(a) When a teacher drops a small piece of sodium into a trough of cold water, she observes bubbles of gas.
Give two other observations that would be made when sodium reacts with cold water. (2)
1 .......................................................................................................................................... .............................................................................................................................................
2 .......................................................................................................................................... .............................................................................................................................................
(b) Lithium reacts with fluorine to form the compound lithium fluoride.
(i) Give a chemical equation for this reaction. (1) .............................................................................................................................................
(ii) Give a test to show that lithium fluoride contains lithium ions. (2) ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. .............................................................................................................................................
2) This question is about the elements in Group 1 of the Periodic Table and their reactions with water.
(a) State why sodium and potassium are in Group 1 of the Periodic Table. (1) ............................................................................................................................................. .............................................................................................................................................
(b) A reaction occurs when a small piece of sodium is added to a large volume of water in a trough.
(i) Give two observations that you would make during this reaction. (2)
1 .......................................................................................................................................... .............................................................................................................................................
2 .......................................................................................................................................... .............................................................................................................................................
(ii) After the reaction has finished, a few drops of universal indicator are added to the solution in the trough. Explain the final colour of the universal indicator. (2) ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................
3) This question is about some of the Group 1 elements and their compounds. (a) A teacher adds a small piece of lithium to water in a trough. (i) Give three observations that are made when lithium reacts with water. (3)
1 ..........................................................................................................................................
2 ..........................................................................................................................................
3 ..........................................................................................................................................
(ii) After the reaction has finished, the teacher adds a few drops of universal indicator to the solution in the trough.
Explain the colour of the universal indicator after it is added to the solution. (2) ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. .............................................................................................................................................
(iii) Write a chemical equation for the reaction of lithium with water. (2) .............................................................................................................................................
(b) A student does a flame test to see if a white solid contains sodium ions. She cleans a platinum wire before using it for the flame test.
(i) Explain why the student needs to clean the platinum wire. (2) ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. .............................................................................................................................................
4) Lithium, sodium and potassium are the first three elements in Group 1 of the Periodic Table. (a) Suggest why these three elements are all stored in paraffin oil. (1) ............................................................................................................................................. ............................................................................................................................................. .............................................................................................................................................
(b) Caesium, Cs, is below potassium in Group 1.
(i) Give a similarity and a difference between the reactions of potassium with water and caesium with water. (2) similarity................................................................................................................................. ............................................................................................................................................. difference............................................................................................................................... .............................................................................................................................................
(ii) Give the chemical equation for the reaction between caesium and water. (2) .............................................................................................................................................
(Total for question = 5 marks)
5) This question is about sodium and potassium. A trough is filled with water and a few drops of phenolphthalein indicator are added.
(a) A small piece of sodium is dropped into the water. One of the products of the reaction is an alkali.
(i) Complete the chemical equation for the reaction of sodium with water. (2)
(ii) Identify the ion that causes the solution to become alkaline.
(1) .............................................................................................................................................
(iii) Give three observations that would be made when sodium reacts with water. (3)
1 .......................................................................................................................................... .............................................................................................................................................
2 .......................................................................................................................................... .............................................................................................................................................
3 .......................................................................................................................................... .............................................................................................................................................
Subtopic 2b: Group 7 (halogens) – chlorine, bromine and iodine
1) Astatine, bromine, chlorine, fluorine and iodine are all halogens. They are found in Group 7 of the Periodic Table.
(a) Predict which halogen has the lightest colour. (1) .............................................................................................................................................
(b) Name a halogen that is a solid at room temperature. (1) .............................................................................................................................................
(c) Bromine can be obtained from the bromide ions in sea water.
Chlorine is bubbled into sea water. The chlorine oxidises the bromide ions to bromine atoms.
The bromine atoms then form bromine molecules.
(i) Complete the equation to show how bromine atoms are formed from bromide ions.
(1) Cl2 + ........................... Br− → 2Cl− + ........................... Br
(ii) State why this reaction is described as the oxidation of bromide ions. (1) ............................................................................................................................................. .............................................................................................................................................
(iii) Write an equation to show how bromine atoms form bromine molecules. (1) .............................................................................................................................................
(d) Boron and fluorine form a covalent compound that has the molecular formula BF3
Draw a dot-and-cross diagram to show the arrangement of the outer electrons in a molecule of BF3
Use crosses to represent the outer electrons of boron.
Use dots to represent the outer electrons of fluorine.
2) This question is about elements in Group 7 of the Periodic Table and their compounds.
(a) (i) Give the name of this group of elements. (1) .............................................................................................................................................
(ii) State the colour of chlorine gas. (1) .............................................................................................................................................
(c) A student compares the reactivity of the elements bromine, chlorine and iodine.
He mixes these pairs of solutions and observes the reactions that occur. • chlorine solution and potassium bromide solution • bromine solution and potassium iodide solution Explain how the reactions can be used to show the order of reactivity of the three elements. Include the colour change that the student would observe in each reaction. (6) ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. .............................................................................................................................................
(Total for question = 8 marks)
3) Use the Periodic Table to help you answer this question.
(a) Identify the element with atomic number 7 (1) .............................................................................................................................................
(b) Identify a solid non-metallic element in Period 3 (1) .............................................................................................................................................
(c) Name an element in Group 7 that is a liquid at room temperature. (1) .............................................................................................................................................
(d) State the relative atomic mass of the element that is in Group 4 and Period 4 (1) .............................................................................................................................................
4) This question is about Group 7 elements and their reactions.
(a) Fluorine has the smallest atoms in Group 7.
The diagram shows the electronic configuration of a fluorine atom.
(i) State why fluorine has the smallest atoms in Group 7. (1) ............................................................................................................................................. .............................................................................................................................................
Subtopic 2c: Gases in the atmosphere
1) This question is about gases in the atmosphere.
(a) The box gives the names of some gases in the atmosphere
Choose gases from the box to answer these questions. Each gas may be used once, more than once or not at all.
(i) Identify a noble gas. (1)
.............................................................................................................................................
(ii) Identify a gas that makes up about 78% of the atmosphere. (1) .............................................................................................................................................
(iii) Identify a greenhouse gas. (1)
.............................................................................................................................................
(iv) Identify a gas produced by the thermal decomposition of calcium carbonate. (1) .............................................................................................................................................
(b) Sulfur reacts with oxygen to produce sulfur dioxide gas.
(i) Write a chemical equation for this reaction. (1) .............................................................................................................................................
(ii) State an environmental problem caused when sulfur dioxide gas dissolves in water in the atmosphere. (1) ............................................................................................................................................. .............................................................................................................................................
(Total for question = 6 marks)
2) This question is about gases in the air.
The pie chart represents the percentages of gases in dry, unpolluted air.
Gases with percentages of less than 1% in air are called trace gases.
(b) One of the trace gases is carbon dioxide.
(ii) Name an environmental problem that is caused by the percentage of carbon dioxide increasing in the atmosphere. (1) .............................................................................................................................................
(iii) Name the trace gas with the highest percentage in dry, unpolluted air. (1) .............................................................................................................................................
(c) Rainwater is acidic because carbon dioxide dissolves in water to form carbonic acid. Acid rain is more acidic than rainwater because acidic pollutant gases also dissolve in water. (i) Give the name of the acid that forms when nitrogen dioxide dissolves in water. (1)
.............................................................................................................................................
(ii) Name another pollutant gas that also forms acid rain. (1) .............................................................................................................................................
(Total for question = 6 marks)
3) State what is meant by the term thermal decomposition. (1) ............................................................................................................................................. .............................................................................................................................................
(Total for question = 1 marks
4) State an environmental problem caused by carbon dioxide. (1) ............................................................................................................................................. .............................................................................................................................................
(Total for question = 1 marks)
5) Magnesium is a metal that burns in air.
(i) State one observation made during the combustion of magnesium metal. (1) ............................................................................................................................................. .............................................................................................................................................
(ii) State one chemical property of the product of combustion that can be used to classify magnesium as a metal. (1) ............................................................................................................................................. .............................................................................................................................................
(Total for question = 2 marks)
Subtopic 2d: Reactivity series
1) A metal is added to copper(II) sulfate solution.
A displacement reaction only occurs if the metal added is more reactive than copper. metal + copper(II) sulfate → metal sulfate + copper
Displacement reactions are exothermic.
The more reactive the metal added, the greater the temperature rise.
A student uses the following method in an experiment to compare the reactivities of different metals:
• pour some copper(II) sulfate solution into a boiling tube and record its temperature using a thermometer
• add some metal to the tube and stir with the thermometer
• record the maximum temperature of the contents of the tube.
He repeats the method using the same amount, in moles, of different metals.
(a) To make the experiment valid, he starts with the copper(II) sulfate solution and the added metal at the same temperature. State two other variables that must be controlled if the experiment is to be valid. (2)
1 .......................................................................................................................................... .............................................................................................................................................
2 .......................................................................................................................................... .............................................................................................................................................
(b) Another student uses the same method three times for each of the metals E, F, G and H. The table shows her results for these metals.
(i) The student calculates the mean temperature increase for metals E and F.
She does not include anomalous values in her calculations.
Calculate the mean temperature increase for metals G and H, ignoring any anomalous values.
Write your answers in the table. (2)
(ii) Explain which metal is the most reactive. (2) ............................................................................................................................................. .............................................................................................................................................
(iii) Explain which metal is less reactive than copper. (2) ............................................................................................................................................. .............................................................................................................................................
(Total for question = 8 marks)
2) (a) Two substances are needed to cause iron to rust. Name these two substances. (2) 1 .......................................................................................................................................... 2 ..........................................................................................................................................
(b) The box gives the names of some substances
Use words from the box to answer these questions.
(i) Give the name of a non-metallic element. (1) .............................................................................................................................................
(ii) Give the name of a compound. (1) .............................................................................................................................................
(iii) Give the name of the metal that is lowest in the reactivity series. (1) .............................................................................................................................................
(Total for question = 5 marks)
3) This question is about rusting.
(a) A simplified formula for rust is Fe2O3
(i) Name the two substances needed for iron to rust. (2)
1 ..........................................................................................................................................
2 ..........................................................................................................................................
(ii) Give the chemical name for rust. (1) .............................................................................................................................................
(iii) What type of reaction occurs in the rusting of iron?
(1) A combustion B neutralisation C oxidation D thermal decomposition
(b) Some iron objects are coated with a layer of zinc to prevent rusting.
(i) Name this type of rust prevention. (1) .............................................................................................................................................
(ii) Explain how this type of rust prevention continues to protect iron when the layer of zinc is damaged. (2) ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. .............................................................................................................................................
(iii) Give two other methods used to prevent iron from rusting. (2)
1 .......................................................................................................................................... .............................................................................................................................................
2 .......................................................................................................................................... .............................................................................................................................................
(Total for question = 9 marks)
4)
(b) (i) State which metal, W, X, Y or Z, could be copper. (1)
.............................................................................................................................................
(ii) State which metal, W, X, Y or Z, could be magnesium. (1)
.............................................................................................................................................
(c) A displacement reaction can also be used to decide the order of reactivity of two metals.
State two observations made when an excess of magnesium powder is added to an aqueous solution of copper(II) sulfate. (2)
1 .......................................................................................................................................... .............................................................................................................................................
2 .......................................................................................................................................... .............................................................................................................................................
(Total for question = 5 marks)
Subtopic 2e: Extraction of metals
1) 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.
(a) (i) State the name given to rocks that contain metal compounds used in the extraction of metals. (1) .............................................................................................................................................
(ii) Name a metal that is found as an uncombined element in the Earth's crust. (1) .............................................................................................................................................
(b) Carbon extraction and electrolysis are two methods of obtaining a metal from a compound.
(i) Explain, without giving practical details, which method is most suitable to obtain calcium from calcium chloride. (2) ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. .............................................................................................................................................
(ii) Explain, without giving practical details, which method is most suitable to obtain lead from lead oxide. (2) ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. .............................................................................................................................................
(c) Explain, using a labelled diagram, why lead metal is malleable. (3)
(d) Aluminium is extracted from aluminium oxide.
The overall equation for the process is 2Al2O3 → 4Al + 3O2
Calculate the maximum mass, in grams, of aluminium that could be obtained from 1.275 kg of aluminium oxide. (3)
mass = ........................................................... g
(Total for question = 12 marks)
2) Zinc metal is obtained from sulfide ores.
The most common ore of zinc is sphalerite, which contains zinc sulfide (ZnS) and a small amount of cadmium sulfide (CdS).
The stages involved in the extraction of zinc from sphalerite are: Stage 1 Sphalerite is strongly heated in air.
2ZnS(s) + 3O2(g) → 2ZnO(s) + 2SO2(g)
2CdS(s) + 3O2(g) → 2CdO(s) + 2SO2(g)
Stage 2 The mixture of oxides is reacted with sulfuric acid.
ZnO(s) + H2SO4(aq) → ZnSO4(aq) + H2O(l)
CdO(s) + H2SO4(aq) → CdSO4(aq) + H2O(l)
Stage 3 Zinc dust is added to the solution containing zinc sulfate and cadmium sulfate to remove the cadmium ions.
Cd2+(aq) + Zn(s) → Cd(s) + Zn2+(aq)
Stage 4 The solid cadmium is filtered off and the pure zinc sulfate solution is electrolysed.
(a) State how the reaction in stage 3 shows that zinc is more reactive than cadmium. (1) ............................................................................................................................................. .............................................................................................................................................
(b) (i) During the electrolysis in stage 4, zinc is deposited on the cathode.
Write an ionic half-equation for the reaction that occurs. (1)
.............................................................................................................................................
(ii) Complete the ionic half-equation for the reaction occurring at the anode. .....................
H2O → .....................H+ + O2 + ..................... e− (1)
(iii) Explain how the pH of the solution surrounding the anode changes during the electrolysis. (2) ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. .............................................................................................................................................
(c) Zinc is mixed with copper to make the alloy brass. Explain why brass is harder than pure copper. (3) ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. .............................................................................................................................................
(Total for question = 8 marks)
3) State what is meant by the term alloy. (1) ............................................................................................................................................. .............................................................................................................................................
(ii) Explain why magnalium is harder than aluminium. (3) ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. .............................................................................................................................................
(Total for question = 4 marks)
Subtopic 2f: Acids, alkalis and titrations
1) This question is about acids, alkalis and indicators.
(a) Which of these is the colour of litmus indicator in an acidic solution? (1)
A blue
B orange
C red
D yellow
(b) Which of these is the pH value of a neutral solution? (1)
A 0
B 4
C 7
D 14
(c) Which of these describes a solution with a pH value of 9? (1)
A strongly acidic
B strongly alkaline
C weakly acidic
D weakly alkaline (d)
Which of these is the chemical formula of an acid? (1)
A HNO3
B H2O
C NaCl
D NaOH
(e) Name the type of reaction that occurs when an acid reacts with an alkali. (1) .............................................................................................................................................
(f) Name the two products of the reaction between hydrochloric acid and potassium hydroxide. (2)
1 ..........................................................................................................................................
2 ..........................................................................................................................................
(Total for question = 7 marks)
2) A student investigates the reaction between sodium hydroxide solution and dilute sulfuric acid.
He does a titration to find the concentration of the sulfuric acid.
This is his plan for the titration.
There are some mistakes and omissions in his plan.
• rinse a conical flask with the sodium hydroxide solution
• use a measuring cylinder to measure out 25 cm3 of the sodium hydroxide solution and add it to the conical flask
• add a few drops of methyl orange indicator to the conical flask
• rinse a burette with water and then fill it with the sulfuric acid
• add the acid from the burette to the conical flask until the indicator changes colour at the end-point of the titration
• record the final burette reading
(a) Give the colour change of the methyl orange indicator at the end-point. (2)
from ........................................ to ........................................
(b) Describe four changes that the student could make to improve his plan. (4)
1 .......................................................................................................................................... ............................................................................................................................................. .............................................................................................................................................
2 .......................................................................................................................................... ............................................................................................................................................. .............................................................................................................................................
3 .......................................................................................................................................... ............................................................................................................................................. .............................................................................................................................................
4 .......................................................................................................................................... ............................................................................................................................................. .............................................................................................................................................
(Total for question = 6 marks)
3) This question is about some compounds of the elements in Group 4 of the Periodic Table.
(a) When carbon dioxide dissolves in water, a weak acid forms.
(i) Which of these could be the pH of this weak acid? (1)
A 1
B 5
C 7
D 9
(ii) Which of these is a correct statement about acids? (1)
A acids contain OH− ions
B acids are electron donors
C acids are proton acceptors
D acids are proton donors
(b) When lead(II) carbonate is heated, lead(II) oxide and carbon dioxide form.
(i) Give the name of this type of reaction. (1) .............................................................................................................................................
(ii) Complete the equation for this reaction. (1)
PbCO3 → .............................................. + ..............................................
(Total for question = 4 marks)
4) This question is about sodium and potassium. A trough is filled with water and a few drops of phenolphthalein indicator are added.
(a) A small piece of sodium is dropped into the water. One of the products of the reaction is an alkali.
(i) Complete the chemical equation for the reaction of sodium with water. (2)
(ii) Identify the ion that causes the solution to become alkaline. (1) .............................................................................................................................................
(Total for question = 3 marks)
5) A student does a titration using dilute sulfuric acid to find the concentration of a solution of potassium hydroxide.
The student adds 25.0 cm3 of the potassium hydroxide solution to a conical flask.
He then adds a few drops of methyl orange indicator. The student does the titration four times. (a)
(i) Name the piece of apparatus the student should use to add the potassium hydroxide solution. (1) .............................................................................................................................................
(ii) What is the colour of methyl orange in an alkaline solution? (1)
A blue
B orange
C red
D yellow
(Total for question = 2 marks)
Subtopic 2g: Acids, bases and salt preparations
1) A student investigates the reaction between sodium hydroxide solution and dilute sulfuric acid. He does a titration to find the concentration of the sulfuric acid. This is his plan for the titration.
There are some mistakes and omissions in his plan.
• rinse a conical flask with the sodium hydroxide solution
• use a measuring cylinder to measure out 25 cm3 of the sodium hydroxide solution and add it to the conical flask
• add a few drops of methyl orange indicator to the conical flask
• rinse a burette with water and then fill it with the sulfuric acid
• add the acid from the burette to the conical flask until the indicator changes colour at the end-point of the titration
• record the final burette reading
(a) Give the colour change of the methyl orange indicator at the end-point. (2)
from ........................................ to ........................................
(b) Describe four changes that the student could make to improve his plan. (4)
1 .......................................................................................................................................... ............................................................................................................................................. .............................................................................................................................................
2 .......................................................................................................................................... ............................................................................................................................................. .............................................................................................................................................
3 .......................................................................................................................................... ............................................................................................................................................. .............................................................................................................................................
4 .......................................................................................................................................... ............................................................................................................................................. .............................................................................................................................................
(Total for question = 6 marks)
2) This question is about sodium and potassium. A trough is filled with water and a few drops of phenolphthalein indicator are added.
(a) A small piece of sodium is dropped into the water. One of the products of the reaction is an alkali.
(i) Complete the chemical equation for the reaction of sodium with water. (2)
(ii) Identify the ion that causes the solution to become alkaline. (1) .............................................................................................................................................
(Total for question = 3 marks)
(b) Ammonium sulfate is often used as a fertiliser. It is prepared by reacting ammonia (NH3) with sulfuric acid (H2SO4). (i) Name the type of reaction that occurs between ammonia and sulfuric acid. (1) .............................................................................................................................................
(ii) Write a chemical equation for the reaction of ammonia with sulfuric acid. (1) .............................................................................................................................................
(Total for question = 2 marks)
3) A student wants to prepare sodium chloride crystals from sodium hydroxide solution and dilute hydrochloric acid.
He does a titration to find the volume of dilute hydrochloric acid needed to neutralise the sodium hydroxide solution.
This is his method.
• add 25.0 cm3 of sodium hydroxide solution to a conical flask
• add a few drops of phenolphthalein indicator to the conical flask
• titrate the solution with the hydrochloric acid
(a) Name a suitable piece of apparatus that the student should use to measure 25.0 cm3 of sodium hydroxide solution. (1) .............................................................................................................................................
(b) (i) Give the colour of the phenolphthalein indicator in sodium hydroxide solution and in hydrochloric acid. (2)
colour in sodium hydroxide solution ............................................................................................................................... colour in hydrochloric acid .............................................................................................................................................
(ii) Suggest why universal indicator is never used in a titration. (1) ............................................................................................................................................. .............................................................................................................................................
(c) The student finds that 21.50 cm3 of hydrochloric acid is needed to neutralise 25.0 cm3 of sodium hydroxide solution.
(i) Describe what the student should do next to prepare a pure solution of sodium chloride. (2) ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. .............................................................................................................................................
(ii) Describe how the student could obtain dry crystals of sodium chloride from the pure sodium chloride solution. (4) ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. .............................................................................................................................................
(Total for question = 10 marks)
4) This question is about barium chloride.
(a) Barium chloride can be made by reacting barium carbonate with dilute hydrochloric acid.
The chemical equation for the reaction is
Describe a method to produce dry crystals of hydrated barium chloride, starting with barium carbonate powder and dilute hydrochloric acid. (6)
............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. .............................................................................................................................................
(Total for question = 6 marks)
5) This question is about salts.
(a) Soluble salts can be prepared by the reaction between a metal oxide and an acid.
The equation for this type of reaction is metal oxide + acid → salt + water
(i) State the name given to this type of reaction. (1) .............................................................................................................................................
(ii) State, in terms of protons, what happens in this reaction. (1) ............................................................................................................................................. .............................................................................................................................................
(b) (i) A student is given 50 cm3 of dilute sulfuric acid and a bottle of solid copper(II) carbonate.
Describe the method that the student should use to prepare a saturated solution of copper(II) sulfate.
In your answer, refer to the pieces of apparatus that the student should use. (5) ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. .............................................................................................................................................
(Total for question = 7 marks)
6. Sodium chloride is a soluble salt.
(a) Name the acid and the alkali that can be used to make sodium chloride. (2)
acid .............................................................................................................................................
alkali .............................................................................................................................................
(b) A teacher drops a bottle containing sodium chloride.
The bottle breaks when it hits the floor. The teacher sweeps up the mixture of sodium chloride and glass.
Describe how the teacher can obtain a pure, dry sample of sodium chloride from the mixture. (4)
............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. .............................................................................................................................................
(Total for question = 6 marks)
Subtopic 2h: Chemical Tests
1) Iron reacts with dilute sulfuric acid to form a salt called iron(II) sulfate.
The formula of iron(II) sulfate is FeSO4
(b) Some iron filings are added to dilute sulfuric acid.
The mixture is warmed and hydrogen gas is given off.
(iii) Give the test for hydrogen gas. (1) .............................................................................................................................................
(Total for question = 1 marks)
2) Oxygen can be prepared from hydrogen peroxide using a catalyst.
(a) Which is a correct statement about oxygen? (1)
A it burns with a squeaky pop
B it relights a glowing splint
C it turns blue litmus red
D it turns limewater milky
(Total for question = 1 marks)
3) A solution of hydrogen peroxide decomposes when a catalyst of manganese(IV) oxide is added.
The products of the reaction are water and oxygen.
(a) Complete the chemical equation for this reaction. (1)
.......................... H2O2 → ............................... H2O + ............................... O2
(b) Give a test for oxygen. (1)
............................................................................................................................................. .............................................................................................................................................
(Total for question = 2 marks)
(b) Describe a test for carbon dioxide. (2) ............................................................................................................................................. ............................................................................................................................................. .............................................................................................................................................
(Total for question = 2 marks)
4) This question is about ammonia gas, NH3
(a) Ammonia can be prepared in a laboratory from the reaction between ammonium chloride, NH4Cl, and sodium hydroxide. The other products of the reaction are sodium chloride and water.
(ii) Give a test for ammonia gas. (2)
............................................................................................................................................. .............................................................................................................................................
(Total for question = 2 marks)
5) This question is about sodium oxide, Na2O
(d) Give a test to show that sodium oxide contains sodium ions. (2) ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. .............................................................................................................................................
(Total for question = 2 marks)
6) This question is about some of the alkali metals and their compounds.
(ii) Give a test to show that lithium fluoride contains lithium ions. (2) ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. .............................................................................................................................................
(Total for question = 2 marks)
7) This question is about some of the Group 1 elements and their compounds.
(b) A student does a flame test to see if a white solid contains sodium ions.
She cleans a platinum wire before using it for the flame test.
(i) Explain why the student needs to clean the platinum wire. (2) ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. .............................................................................................................................................
(ii) Which of these is the colour of the flame if the solid contains sodium ions? (1)
A green
B lilac
C red
D yellow
(Total for question = 3 marks)
8) This question is about metals in Group 1 of the Periodic Table.
When these metals are added to water, they form hydrogen gas and an alkaline solution.
(a) A teacher adds a small piece of lithium to a trough of water to form a solution.
She dips a piece of platinum wire into the solution.
She then places the wire into a hot Bunsen flame and the flame changes colour.
(i) State the new colour of the flame. (1) .............................................................................................................................................
(ii) Give the formula of the ion responsible for the new colour. (1) ............................................................................................................................................. ............................................................................................................................................. (2)
(Total for question = 4 marks)
9) This question is about lithium carbonate.
(b) (i) Give a test to show that lithium carbonate contains lithium ions. (2)
test ...................................................................................................................................... .............................................................................................................................................
result ................................................................................................................................... .............................................................................................................................................
(ii) Describe a test to show that lithium carbonate contains carbonate ions. (3)
test ...................................................................................................................................... ............................................................................................................................................. ............................................................................................................................................. .............................................................................................................................................
result ................................................................................................................................... .............................................................................................................................................
(c) Lithium carbonate decomposes when heated to produce lithium oxide and carbon dioxide.
Complete the chemical equation for this reaction. (1)
Li2CO3 → ............................................... + ...............................................
(Total for question = 6 marks)
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