Chemistry 0620 · IGCSE
Elements, compounds and mixtures
100 practice questions on Elements, compounds and mixtures, with worked solutions and instant marking.
Unpolluted air is made up of nitrogen, oxygen and trace amounts of other gases. The table does not include the noble gases. Which row gives the composition of dry, unpolluted air?
Feb/March 2016
In which row are the substances classified correctly?
Feb/March 2016
Which row shows the substances classified correctly?
Feb/March 2016
The table beneath shows information about particles. Fill in the missing entries. The first row has already been completed for you.
Feb/March 2016
Two separate samples, one of anhydrous copper(II) sulfate and the other of hydrated copper(II) sulfate, are heated. Which row gives the correct colour changes?
Feb/March 2018
Complete the table below.
Feb/March 2019
Which of the following statements about lime (calcium oxide) and limestone (calcium carbonate) are correct?
Feb/March 2020
A set of compounds is listed below. aluminium oxide calcium bromide calcium oxide ethane ethene hydrogen chloride methane nitrogen dioxide potassium iodide potassium manganate(VII) sodium chloride Use only compounds from the list above to answer the questions that follow. Each compound may be chosen once, chosen more than once, or not chosen at all.
Feb/March 2020
State one industrial use of calcium carbonate.
Feb/March 2021
The pie chart shows the composition of natural gas. Which sector shows methane?
Feb/March 2021
For what industrial purpose is calcium carbonate used?
Feb/March 2021
The pie chart shows the composition of natural gas. Which section corresponds to methane?
Feb/March 2021
This question concerns sulfur and compounds of sulfur.
Feb/March 2021
Which statement concerning hydrated cobalt(II) chloride is correct?
Feb/March 2023
Which statement gives the description of a compound?
Feb/March 2023
A list of symbols and formulae is given below. Br$_2$ CH$_4$ C$_2$H$_4$ Cl$^-$ CO$_2$ Cr$^{3+}$ Cu$^{2+}$ H$_2$ K$^+$ N$_2$ N$^{3-}$ O$_2$ SO$_4^{2-}$ Use these symbols and formulae to answer the questions that follow. Each symbol or formula can be used once, more than once or not at all.
Feb/March 2023
Which diagram shows a mixture of compounds?
Feb/March 2024
Which statement describes a property of potassium iodide?
Feb/March 2024
The substances below are listed. brass calcium oxide carbon monoxide diamond glucose hydrogen litmus magnesium bromide methyl orange sodium chloride stainless steel thymolphthalein water zinc oxide Use these substances to answer the questions that follow. Each substance may be chosen once, more than once, or not used at all.
Feb/March 2024
Which statement is false?
May/June 2017
What colour change occurs when hydrated cobalt(II) chloride is heated until it changes into anhydrous cobalt(II) chloride?
May/June 2017
Which statement is incorrect?
May/June 2017
Sulfur is placed in Group VI of the Periodic Table.
May/June 2017
Which statement below is correct?
May/June 2018
Which statement concerning sulfur and its compounds is incorrect?
May/June 2018
Which row gives the uses of sulfur and sulfur dioxide?
May/June 2018
The ‘lead’ in a pencil is formed from a mixture of graphite and clay. When the proportion of graphite is increased, the pencil moves across the paper more readily. Which statement explains this observation?
May/June 2018
What name is used for a pure substance consisting of more than one type of atom?
May/June 2018
The ‘lead’ in a pencil consists of a blend of graphite and clay. If the percentage of graphite is increased, the pencil moves over the paper more easily. Which statement accounts for this observation?
May/June 2018
The eight gases listed are shown below. ammonia argon carbon dioxide helium hydrogen methane neon sulfur dioxide
May/June 2018
Below are the symbols and formulae for some elements and compounds. Ar Ca(OH)$_2$ Cl$_2$ CO$_2$ Cu Fe SO$_2$ V$_2$O$_5$ Use only the elements or compounds in the list to answer the questions that follow. Each item may be chosen once, more than once, or not at all. State which element or compound is used:
May/June 2018
The diagrams display some of the structures of five substances, A, B, C, D and E.
May/June 2019
The diagram depicts part of the structures of five substances, A, B, C, D and E.
May/June 2019
Eight substances are listed below. aluminium oxide calcium oxide ethanol nitrogen iron(III) oxide methane oxygen silicon(IV) oxide Use the substances to answer the questions that follow. A substance may be selected once, more than once, or not selected at all. State which substance is:
May/June 2019
Which of the following statements is correct?
May/June 2021
Which row gives the uses of sulfur and sulfur dioxide?
May/June 2021
Which of the following statements about calcium carbonate is correct?
May/June 2021
Details for four substances E, F, G and H are given. E, F, G and H are graphite, poly(ethene), sodium chloride and silicon(IV) oxide, but not necessarily in that order. Which substances are E, F, G and H?
May/June 2021
Which products are manufactured using calcium carbonate?
May/June 2022
A set of symbols and formulae is given below. Br⁻ CH₄ CO₂ Cu^{2}⁺ H₂ K⁺ Na⁺ N₂ O₂ U Use only these symbols or formulae to answer the questions that follow. Each one may be used once, reused, or not used at all.
May/June 2022
A list of symbols and formulae is given below. Al$_2$O$_3$ C$_2$H$_5$OH CO$_2$ Fe$_2$O$_3$ H$_2$ He K$^+$ Li$^+$ N$_2$ Na$^+$ O$^{2-}$ Use only these symbols or formulae to answer the questions that follow. Each symbol or formula may be used once, more than once, or not used at all.
May/June 2022
A set of substances is shown. aluminium oxide, carbon dioxide, carbon monoxide, chlorine, copper, glucose, iron(III) oxide, limestone, nitrogen, oxygen Use the substances in the list to answer the questions. Each substance can be chosen once, more than once, or not used at all. State which substance is:
May/June 2022
Which row concerning elements, mixtures and compounds is correct?
May/June 2023
Which statement shows that water is a compound?
May/June 2023
The percentage composition of the gases in Neptune’s atmosphere is shown. Which statement about the atmospheres of Neptune and Earth is correct?
May/June 2023
The diagrams show some elements, compounds and mixtures. Which row identifies the numbered substances?
May/June 2023
Which of the following statements are true?
May/June 2023
Which line about elements, mixtures and compounds is correct?
May/June 2023
The diagrams show several elements, compounds and mixtures. Which row identifies the numbered substances?
May/June 2023
Which substance contains two of the elements present in NPK fertilisers?
May/June 2024
Which statement concerning sulfur is correct?
May/June 2024
The reaction equation for the hydration of anhydrous copper(II) sulfate is given below. $\text{CuSO}_4 + 5\text{H}_2\text{O} \rightarrow \text{CuSO}_4\cdot5\text{H}_2\text{O}$ What colour change is seen in this reaction?
May/June 2024
Which statement is accurate?
May/June 2024
Which statement indicates that a liquid is pure water?
May/June 2024
A mixture includes four substances: calcium nitrate, iron(II) sulfate, oxygen, and water. Which statement best describes the mixture?
May/June 2024
Which statement indicates that a sample of water is pure?
May/June 2024
Some details about three gases, P, Q and R, are provided. Gas P is produced when magnesium reacts with dilute hydrochloric acid. Gas Q accounts for $78\%$ of the air. Gas R is formed when gas P reacts with gas Q. What is gas R?
May/June 2024
Details for four substances, W, X, Y and Z, are given below. W, X, Y and Z are graphite, poly(ethene), sodium chloride and silicon(IV) oxide, although these are not listed in the correct order. Identify W, X, Y and Z.
May/June 2024
P and Q are both able to conduct electricity. P is a mixture containing two different types of atom. Q contains only one type of atom. Which row gives the correct description of P and Q?
May/June 2024
Complete Table 2.1 by filling in the missing entries.
May/June 2024
Complete Table 2.1 by filling in the missing entries.
May/June 2024
Which substance consists of one element together with one compound?
May/June 2025
Which diagram represents a mixture made up of an element and a compound?
May/June 2025
Which statement correctly describes elements and their atoms?
May/June 2025
Water is added in separate tests to anhydrous copper(II) sulfate and to anhydrous cobalt(II) chloride. Which row shows the colour changes?
May/June 2025
When $65\,\text{g}$ of zinc reacts with $32\,\text{g}$ of sulfur, $97\,\text{g}$ of zinc sulfide is formed. When $65\,\text{g}$ of zinc reacts with $40\,\text{g}$ of sulfur, the mass of zinc sulfide formed is still $97\,\text{g}$. Which statement best accounts for this result?
May/June 2025
Two statements concerning hydrogen are given. Which of the following conclusions about these statements is correct?
May/June 2025
A set of substances is given below. aluminium ammonia argon bromine carbon dioxide fluorine iron magnesium magnesium chloride nitrogen oxygen potassium Use the list to answer the questions that follow. Each substance can be chosen once, more than once, or not at all. State which substance is:
May/June 2025
The substances below are listed. aluminium bromine calcium carbon dioxide iron magnesium magnesium oxide neon oxygen potassium sulfur dioxide Use these substances to answer the questions that follow. Each substance may be selected once, more than once, or not used at all.
May/June 2025
A selection of substances is given below. calcium calcium oxide carbon carbon dioxide chlorine copper gold iodine neon nitrogen oxygen potassium sulfur dioxide Use these substances to answer the questions that follow. Each substance may be chosen once, chosen more than once, or not chosen at all. State which substance is:
May/June 2025
This question is about sea water and the substances present in it.
May/June 2025
The substances below are listed. bauxite calcium oxide ethanol graphite methane nitrogen oxygen propane propene sulfur dioxide Use the list of substances to answer the questions. Each substance may be chosen once, more than once, or not at all.
May/June 2025
Air is a blend of gases. Which gas occurs in the greatest amount?
Oct/Nov 2016
Which box represents limestone?
Oct/Nov 2016
Air is a blend of gases. Which gas is found in the greatest quantity?
Oct/Nov 2016
Air consists of a mixture of gases. Which gas is found in the greatest amount?
Oct/Nov 2016
Air consists of a mixture of gases. Which gas is found in the greatest amount?
Oct/Nov 2016
Which box matches limestone?
Oct/Nov 2016
Petroleum is a significant fossil fuel. Which row gives the correct description of petroleum?
Oct/Nov 2016
Air consists of a mixture of gases. Which gas is present in the greatest amount?
Oct/Nov 2016
Air is a blend of gases. Which gas is found in the greatest quantity?
Oct/Nov 2016
Cement is produced by heating clay together with limestone. Part of the limestone, which is calcium carbonate, decomposes to make calcium oxide and a gas that turns limewater milky.
Oct/Nov 2016
Which statement is incorrect?
Oct/Nov 2017
Which diagram illustrates a mixture containing an element and a compound?
Oct/Nov 2017
Which of the following statements is incorrect?
Oct/Nov 2017
The diagram presents the particle arrangements of five substances, A, B, C, D and E. Structure A is shown as Br-Br. Structure B is a lattice of Na⁺ and Br⁻ ions. Structure C is drawn as F-Br-F. Structure D is a molecule with a C=C double bond and hydrogen atoms attached. Structure E is shown as Br-C-C-Br with hydrogen atoms attached.
Oct/Nov 2017
The table presents the properties of four substances.
Oct/Nov 2017
The diagram illustrates the structures of five substances, A, B, C, D and E. A is a molecule in which sulfur is double-bonded to two oxygen atoms (sulfur dioxide). B shows alternating NH$_4^+$ and Cl$^-$ ions in a lattice. C shows N≡N. D is a nitrogen atom bonded to three hydrogen atoms. E shows O=C=O. Use only the structures in the diagram to answer the questions below. Each structure may be chosen once, more than once, or not chosen at all.
Oct/Nov 2017
Substances may be grouped as elements, compounds, or mixtures.
Oct/Nov 2017
Salt is mixed with pure water to make an aqueous solution. Which statement is correct?
Oct/Nov 2018
Which of the following statements about sulfur or one of its compounds is correct?
Oct/Nov 2018
Which statement concerning sulfur or one of its compounds is true?
Oct/Nov 2018
Which statement relating to sulfur or one of its compounds is correct?
Oct/Nov 2018
The diagrams illustrate the structures of four substances, R, S, T and U.
Oct/Nov 2018
The substances below are listed by formula. Al Ag CaCO$_3$ CH$_4$ Cl$_2$ Cu SO$_2$ Use only these substances to answer the questions. A substance may be chosen once, more than once, or not chosen at all.
Oct/Nov 2018
Use only the substances in the list below to answer the questions that follow. A substance may be used once, more than once, or not used at all. ammonia bauxite carbon dioxide carbon monoxide hematite oxygen sodium chloride sulfur dioxide
Oct/Nov 2018
Which of the statements is correct?
Oct/Nov 2019
Nitrogen, oxygen and small quantities of other gases make up clean, dry air. The table does not include the noble gases. Which row gives the composition of clean, dry air?
Oct/Nov 2019
Substances P and Q each conduct electricity. P is a mixture containing two different atom types. Q consists of only one atom type. Which row best describes P and Q?
Oct/Nov 2019
Clean, dry air is made up of nitrogen, oxygen and only tiny quantities of other gases. The noble gases are not included in the table. Which row gives the composition of clean, dry air?
Oct/Nov 2019