Chemistry 0620 · IGCSE
Oct/Nov 2017
120 questions from this paper, with worked solutions and instant marking.
The diagram illustrates how the particles are arranged when a substance undergoes a change of state. Which change of state is being shown?
Solids, liquids and gases
A current is passed through concentrated aqueous sodium chloride. Inert electrodes are used. What is produced at the negative electrode?
Electrolysis
Two chemical processes are outlined. • In the combustion of gasoline, energy is ......1...... . • In the electrolysis of sulfuric acid, energy is ......2...... . Which words should fill gaps 1 and 2?
Exothermic and endothermic reactions
As dilute sulfuric acid reacts with aqueous sodium hydroxide, the temperature of the mixture rises. Which words are used to describe this reaction?
Exothermic and endothermic reactions
A graph of the mass of a beaker and its contents is drawn against time. Which graph shows what happens when sodium carbonate reacts with an excess of dilute hydrochloric acid in an open beaker?
Rate of reaction
When blue copper(II) sulfate is heated, a white solid and water are produced. If water is added to this white solid, it turns blue again and gives out heat. Which terms describe the blue copper(II) sulfate and the reactions?
Exothermic and endothermic reactions
Which changes would raise the rate of reaction between calcium carbonate and dilute hydrochloric acid? 1 increasing the concentration of the acid 2 increasing the temperature 3 increasing the size of the pieces of calcium carbonate
Rate of reaction
The equations for two reactions P and Q are shown below. P: $2\text{NaNO}_2 + \text{O}_2 \rightarrow 2\text{NaNO}_3$ Q: $2\text{HgO} \rightarrow 2\text{Hg} + \text{O}_2$ For which of these reactions does oxidation of the underlined substance take place?
Redox
Which of the following is not a typical property of acids?
The characteristic properties of acids and bases
Magnesium, phosphorus and chlorine are elements in one period of the Periodic Table. Which row identifies the type of oxide formed by each element?
Oxides
Zinc sulfate is produced by reacting an excess of zinc oxide with dilute sulfuric acid. The leftover zinc oxide is then separated from the solution. Which process is used to recover solid zinc sulfate from this solution?
Separation and purification
What method can be used to separate a salt-and-water mixture so that both components are obtained?
Separation and purification
What is used to detect chlorine?
Identification of ions and gases
Which of the following statements about trends across a period in the Periodic Table are correct? 1 Aluminium shows greater metallic character than sodium. 2 Beryllium shows greater metallic character than carbon. 3 Boron shows greater metallic character than lithium. 4 Magnesium shows greater metallic character than silicon.
Arrangement of elements
Astatine is an element in Group VII of the Periodic Table. Compared with iodine, astatine is ......1...... reactive. The melting point of astatine is ......2...... the melting point of iodine. Compared with bromine, astatine is ......3...... in colour. Which words should go in gaps 1, 2 and 3?
Group VII properties
Which row gives the properties of a typical transition element?
Transition elements
For what reason is argon gas used to fill electric lamps?
Noble gases
What property do all metals have?
Properties of metals
Which material is not used in the large-scale extraction of iron from iron ore?
Extraction of metals
A table lists some reactions of three metals. In which sequence should the metals be placed by reactivity?
Reactivity series
Which two uses of the metals shown are correct?
Uses of metals
The flow chart illustrates the stages used to treat river water so that it becomes drinking water. What happens at stages X and Y?
Water
A student measured out $25.0\,\text{cm}^3$ of dilute hydrochloric acid and poured it into a conical flask. Next, the student added $2.5\,\text{g}$ of solid sodium carbonate and recorded the temperature change of the mixture. Which piece of apparatus should the student use to obtain the most accurate results?
Exothermic and endothermic reactions
What gas makes up more than 30% of air?
Air quality and climate
Iron is a metal that rusts when oxygen and water are present. Mild steel is used for .....1..... and its rusting is stopped by .....2..... . Stainless steel does not rust. It is made by .....3..... iron with another metal. Which words fill gaps 1, 2 and 3?
Corrosion of metals
A mixture releases a gas both on reaction with an acid and on reaction with an alkali. Which ions are present in this mixture?
Identification of ions and gases
When some marble chips (calcium carbonate) are heated strongly, substances X and Y are produced. Substance X is a white solid that reacts with water and releases heat. Substance Y is a colourless gas. What are substances X and Y?
Oxides
Several organic molecule structures are displayed. Which of the structures are alkanes containing four carbon atoms?
Alkanes
A number of the fractions produced by the fractional distillation of petroleum are burned as vehicle fuels. Which two fractions are used as fuels for vehicles?
Fuels
The combustion of fossil fuels gives out heat energy. Which substance is not a fossil fuel?
Fuels
X, Y and Z are three hydrocarbons. $X$: $\text{CH}_2{=}\text{CH}_2$, $Y$: $\text{CH}_3{-}\text{CH}{=}\text{CH}_2$, $Z$: $\text{CH}_3{-}\text{CH}_2{-}\text{CH}{=}\text{CH}_2$. What feature do compounds X, Y and Z all share?
Alkenes
The table indicates which bonds are found and which are absent in compound X. Bonds shown: - C-C ✓ - C=C ✗ - C-H ✓ - C-O ✓ - C=O ✓ - O-H ✓ What type of compound is X?
Formulae, functional groups and terminology
The diagram illustrates a reaction pathway. butane $\xrightarrow{X}$ ethene $\xrightarrow{Y}$ ethanol $\xrightarrow{Z}$ carbon dioxide and water Which row correctly gives the names of the processes X, Y and Z?
Alkanes
Propanone, $\text{C}_3\text{H}_6\text{O}$, exists as a liquid at room temperature. What is the boiling point of pure propanone?
Solids, liquids and gases
Molecules of a substance react together as shown. A number of molecules that each contain a C=C double bond join to make a long-chain molecule containing only C-C single bonds. What type of reaction has occurred?
Polymers
Which of the following statements about the boxes P, Q and R is correct?
Solids, liquids and gases
The numbers of particles in atoms W, X, Y and Z are given below. Which of these statements is correct?
Atomic structure and the Periodic Table
Which row states the type of bonding found in substances 1 and 2?
Simple molecules and covalent bonds
Substances that have giant covalent structures may be used as lubricants and also as cutting tools for hard materials. The diagram illustrates the arrangement of atoms in two giant covalent substances, X and Y. Which statement is correct?
Giant covalent structures
The equation represents the thermal decomposition of magnesium carbonate ($M_r = 84$). $\text{MgCO}_3 \rightarrow \text{MgO} + \text{CO}_2$ What mass of magnesium oxide is produced when $21.0\,\text{g}$ of magnesium carbonate is completely decomposed?
The mole and the Avogadro constant
The melting points and boiling points of four elements are given. For which elements do the particles vibrate around fixed positions at $0^$?
Solids, liquids and gases
The diagram illustrates the electrolysis of two solutions using inert electrodes. Which substance is formed at each electrode?
Electrolysis
Two chemical processes are outlined below. • In the combustion of ethanol, energy is .....1..... . • In the electrolysis of aqueous sodium chloride, energy is .....2..... . Which words should be used to fill gaps 1 and 2?
Exothermic and endothermic reactions
Water is poured onto anhydrous copper(II) sulfate in a test tube. The mixture warms up. Which reaction type and energy-level diagram are correct for this reaction?
Exothermic and endothermic reactions
A graph showing the mass of a beaker and everything inside it is plotted against time. Which graph shows what occurs when sodium carbonate reacts with an excess of dilute hydrochloric acid in an open beaker?
Rate of reaction
When blue copper(II) sulfate is heated, it produces a white solid and water. If water is then added to the white solid, it turns blue and releases heat. Which terms are used to describe the blue copper(II) sulfate and the reactions?
Exothermic and endothermic reactions
An investigation was conducted to determine the rate of reaction when 1 g of solid X reacts with $100\,\text{cm}^3$ of solution Y. The reaction happened too quickly for measurements to be taken. What change could be made to reduce the reaction rate?
Rate of reaction
The equations for reactions P and Q are shown below. $\text{P}\quad 2\text{NaNO}_2 + \text{O}_2 \rightarrow 2\text{NaNO}_3$ $\text{Q}\quad 2\text{HgO} \rightarrow 2\text{Hg} + \text{O}_2$ For which of these reactions does oxidation of the underlined substance take place?
Redox
Which of the following is not a typical property of acids?
The characteristic properties of acids and bases
Elements Q and R both burn when they are put in air. Both oxides that are produced dissolve in water. The solution made from the oxide of element Q changes Universal Indicator to red. The solution made from the oxide of element R changes Universal Indicator to blue. What are Q and R?
Oxides
Copper(II) sulfate may be made by reacting sulfuric acid with an excess of copper(II) carbonate. Why is copper(II) carbonate added in excess?
Preparation of salts
The apparatus shown is used for separating a mixture. Which mixture is it?
Separation and purification
Compound P reacts with hydrochloric acid to form a gas that makes limewater go cloudy. Identify P.
Identification of ions and gases
Which statement concerning nitrogen and phosphorus is incorrect?
Arrangement of elements
Sodium and rubidium are elements in Group I of the Periodic Table. Which statement is correct?
Group I properties
What characteristics do the elements chromium, iron and vanadium share?
Transition elements
What is the reason for using argon gas to fill electric lamps?
Noble gases
Which property is shared by all metals?
Properties of metals
What process is used to obtain iron from hematite in the blast furnace?
Extraction of metals
The table gives some reactions for three metals. In what order should the metals be placed by reactivity?
Reactivity series
Which two uses of the metals displayed are correct?
Uses of metals
The flow diagram illustrates the steps used to treat river water so that drinking water is obtained. What happens at stages X and Y?
Water
In an experiment, a measurement is taken in $\text{cm}^3$. Which apparatus would be used?
Experimental design
Which element from Group VI is a constituent of air?
Arrangement of elements
Iron is a metal that rusts when oxygen and water are both present. Mild steel is used for .....1..... and is protected against rusting by .....2..... . Stainless steel does not rust. It is made by .....3..... iron with another metal. Which words fill gaps 1, 2 and 3?
Corrosion of metals
A chemical reaction is performed on substance X. A gas is released that changes red litmus paper to blue. What is this reaction?
Identification of ions and gases
When some marble chips (calcium carbonate) are heated strongly, substances X and Y are produced. Substance X is a white solid that reacts with water and releases heat. Substance Y is a colourless gas. What are substances X and Y?
Physical and chemical changes
The displayed structures represent four organic compounds. Which of the compounds are unsaturated?
Alkenes
Which statement is incorrect?
Elements, compounds and mixtures
Which equation shows the complete combustion of butane, $\text{C}_4\text{H}_{10}$?
Alkanes
X, Y and Z are three hydrocarbons made up only of carbon and hydrogen. X: $\text{CH}_2=\text{CH}_2$ Y: $\text{CH}_3-\text{CH}=\text{CH}_2$ Z: $\text{CH}_3-\text{CH}_2-\text{CH}=\text{CH}_2$ What feature is shared by compounds X, Y and Z?
Alkenes
The table lists the bonds found in compound X and those that are absent from compound X. Bonds shown: - C-C: present - C=C: not present - C-H: present - C-O: present - C=O: present - O-H: present What type of compound is X?
Carboxylic acids
The diagram illustrates a reaction pathway: butane $\rightarrow$ ethene $\rightarrow$ ethanol $\rightarrow$ carbon dioxide and water Which row gives the names of processes X, Y and Z?
Alkanes
At room temperature, substance Q is a yellow solid, and its boiling point is $445^$. Which temperature might be the melting point of pure Q?
Solids, liquids and gases
The molecules of a substance undergo a reaction as illustrated. A number of molecules that contain $\text{C}=\text{C}$ bonds join to make a long-chain molecule containing only single $\text{C}-\text{C}$ bonds. What type of reaction has occurred?
Polymers
Which diagram illustrates a mixture containing an element and a compound?
Elements, compounds and mixtures
In which pair of atoms is the number of neutrons the same?
Isotopes
In which row do the properties given correspond to the bonding type?
Ions and ionic bonds
Which statement accounts for why graphite is used as a lubricant?
Giant covalent structures
What is the relative formula mass of magnesium nitrate, $\text{Mg(NO}_3\text{)}_2$?
Relative masses of atoms and molecules
Which one of the following statements concerning liquids and gases is correct?
Solids, liquids and gases
The electrolysis of concentrated hydrochloric acid with platinum electrodes is shown. What is seen at each electrode at the beginning of the electrolysis?
Electrolysis
Two chemical processes are given. • When kerosene burns, energy is ……1…… . • When hydrochloric acid is electrolysed, energy is ……2…… . Which words fill gaps 1 and 2?
Exothermic and endothermic reactions
Which reaction absorbs energy from the surroundings?
Exothermic and endothermic reactions
The mass of a beaker together with its contents is shown plotted against time. Which graph shows what occurs when sodium carbonate reacts with an excess of dilute hydrochloric acid in an open beaker?
Rate of reaction
When blue copper(II) sulfate is heated, a white solid and water are produced. If water is then added to the white solid, it turns blue and gives out heat. Which terms name the blue copper(II) sulfate and the reactions?
Exothermic and endothermic reactions
The equation for the reaction of magnesium with hydrochloric acid is shown. $\text{Mg} + 2\text{HCl} \rightarrow \text{MgCl}_2 + \text{H}_2$ The rate of this reaction is investigated with the apparatus shown. Which change would increase the rate of reaction?
Rate of reaction
The reaction equations for P and Q are shown below. P: $2\text{NaNO}_2 + \text{O}_2 \rightarrow 2\text{NaNO}_3$ Q: $2\text{HgO} \rightarrow 2\text{Hg} + \text{O}_2$ For which of these reactions does oxidation of the underlined substance take place?
Redox
Which of the following is not a usual property of acids?
The characteristic properties of acids and bases
When it is added to water, which oxide forms a solution with a pH greater than pH 1 but less than pH 7?
Oxides
Three solids, P, Q and R, each react with dilute sulfuric acid to form zinc sulfate. Gaseous products are made when P and R react. The gas released from the reaction of P will not burn. The gas released from the reaction of R will burn. What are P, Q and R?
Preparation of salts
Which method is used to obtain copper(II) sulfate crystals from an aqueous solution of copper(II) sulfate?
Separation and purification
Which ion gives a green precipitate with aqueous sodium hydroxide that dissolves when excess aqueous sodium hydroxide is added?
Identification of ions and gases
A part of the Periodic Table is shown. Group: I, II, III, IV, V, VI, VII, VIII Element: R, S, T, V, W, X, Y, Z These letters do not represent the chemical symbols. Which statement is true?
Arrangement of elements
The following properties are given for element X. melting point in ^{\circ}C: 98 boiling point in ^{\circ}C: 883 reaction with cold water: releases $\text{H}_2$ gas reaction when heated with oxygen: burns and produces a white solid In which part of the Periodic Table would X be placed?
Group I properties
The table shows several properties of an element. melting point, in ^{\circ}C: 3422 appearance shown by the element: grey appearance shown by the chloride of the element: dark blue density, in $\text{g cm}^{-3}$: 19.2 electrical conductivity in the solid state: good Which other property would you anticipate for this element?
Transition elements
What is the reason argon gas is used to fill electric lamps?
Noble gases
What is one property shared by all metals?
Properties of metals
What substance acts as the reducing agent in the large-scale extraction of iron from iron ore?
Extraction of metals
The table shows some reactions involving three metals. Metal P: reacts with dilute hydrochloric acid - yes; metal oxide reduced by carbon - no Metal Q: reacts with dilute hydrochloric acid - yes; metal oxide reduced by carbon - yes Metal R: reacts with dilute hydrochloric acid - no; metal oxide reduced by carbon - yes In which order do the metals decrease in reactivity?
Reactivity series
Which of the uses of the metals shown are both correct?
Uses of metals
The flow diagram sets out the steps in treating river water so that it can be made into drinking water. river water $\rightarrow$ settling tank $\rightarrow$ stage X $\rightarrow$ stage Y $\rightarrow$ drinking water What happens at stages X and Y?
Water
$25\,\text{cm}^3$ of an alkali are mixed with $20\,\text{cm}^3$ of an acid, and the temperature change is recorded. Which piece of apparatus is not required for this experiment?
Exothermic and endothermic reactions
What substance is formed during the incomplete combustion of methane?
Fuels
Iron is a metal which rusts when oxygen and water are both present. Mild steel is used for .....1..... and its rusting is stopped by .....2..... . Stainless steel does not rust. It is made by .....3..... iron with another metal. Which words go in gaps 1, 2 and 3?
Corrosion of metals
Q is warmed with aqueous sodium hydroxide. The moist red litmus paper becomes blue. What substance is Q?
Identification of ions and gases
When some marble chips (calcium carbonate) are heated strongly, substances X and Y are produced. X is a white solid which reacts with water and gives out heat. Y is a colourless gas. Which substances are X and Y?
Oxides
The structure of compound R is displayed below. (Structural formula of a three-carbon chain with an $\text{OH}$ group attached to the terminal carbon.) What compound is R?
Alcohols
Fuel oil and naphtha are two fractions separated from petroleum. What are the main uses of these fractions?
Fuels
Which substances are produced by the complete combustion of ethanol?
Fuels
X, Y and Z are three different hydrocarbons. $X\ \ \text{CH}_2{=}\text{CH}_2$ $Y\ \ \text{CH}_3{-}\text{CH}{=}\text{CH}_2$ $Z\ \ \text{CH}_3{-}\text{CH}_2{-}\text{CH}{=}\text{CH}_2$ Which feature do compounds X, Y and Z share?
Alkenes
The table indicates which bonds are found in compound X and which bonds are not found in compound X. (Bond table showing presence of C-C, C-H, C-O, C{=}O, O-H bonds and absence of C{=}C bonds.) What kind of compound is X?
Formulae, functional groups and terminology
The diagram illustrates a reaction pathway: $\text{butane} \xrightarrow{X} \text{ethene} \xrightarrow{Y} \text{ethanol} \xrightarrow{Z} \text{carbon dioxide and water}$ Which row gives the names of the processes X, Y and Z?
Alkanes
A portion of liquid X turns blue cobalt(II) chloride paper pink. The sample boils at $102^\circ\text{C}$. Which statements are correct?
Water
The molecules of a substance react with one another in the way shown. (Diagram showing several ethene molecules joining to make a long saturated hydrocarbon chain.) Which type of reaction has occurred?
Polymers
Substance Y is placed into a surplus of hot water. A blue solution is produced, and a brown solid is left behind. The brown solid is then filtered off and dried. The brown solid allows electricity to pass through it. What is Y?
Identification of ions and gases
Which line shows the number of protons, electrons and neutrons present in a zinc atom?
Atomic structure and the Periodic Table
The following four statements concern atoms and ions. Which of these statements are correct?
Ions and ionic bonds
Diagrams X, Y and Z show part of a polymer and two giant covalent structures. Which of X, Y or Z could serve as a cutting tool, and which of X, Y or Z could be used to lower friction?
Giant covalent structures
A compound with the formula $\text{XO}_2$ has a relative formula mass of 64. Which element is X?
Relative masses of atoms and molecules