Feb/March 2023

The particle arrangements in solids, liquids and gases are not the same. Which statement about the molecules in ice, water or steam is correct?

Solids, liquids and gases

The diagram illustrates an electrolysis circuit. At which electrode does hydrogen form?

Electrolysis

Which gases are employed to generate electricity in a fuel cell?

Hydrogen–oxygen fuel cells

A reaction pathway diagram for the reaction is displayed. Which of the following statements about the reaction are correct?

Exothermic and endothermic reactions

Which row gives a description of a chemical change?

Physical and chemical changes

Magnesium powder reacts with an excess of dilute hydrochloric acid to form hydrogen gas. Which of these statements about this reaction are correct?

The characteristic properties of acids and bases

Which statement concerning hydrated cobalt(II) chloride is correct?

Elements, compounds and mixtures

A water-based solution reacts with a solid. The products formed are an alkaline gas, a salt and water. Which aqueous solution and which solid are involved?

The characteristic properties of acids and bases

In industrial plants, calcium oxide, CaO, and calcium hydroxide, Ca(OH)$_2$, are both employed to remove sulfur dioxide, SO$_2$, from flue gases. Which row gives the correct classification of calcium oxide, calcium hydroxide and sulfur dioxide?

Oxides

Copper(II) sulfate is made by adding sulfuric acid to excess copper(II) carbonate. Why is copper(II) carbonate added in excess?

Preparation of salts

A section of the Periodic Table is displayed. Which element has two electrons in its outer shell and three electron shells?

Atomic structure and the Periodic Table

The melting points and boiling points of three elements are given at $1$ atm pressure. Separate samples of argon, nitrogen and oxygen are kept at $-200\,^\circ\text{C}$ and at $1$ atm pressure. How many of the samples are liquids?

Solids, liquids and gases

The following facts are provided for element X: melting point = $64^{\circ}\text{C}$; density = $0.86\,\text{g cm}^{-3}$; reacts vigorously with water. In which part of the Periodic Table is X placed?

Group I properties

The properties of the element titanium, Ti, can be forecast from its position in the Periodic Table. Which row shows the properties of titanium?

Arrangement of elements

Which statement about brass is correct?

Alloys and their properties

Which symbol represents the metal that is used in aircraft manufacture because of its low density?

Uses of metals

What property of stainless steel makes it suitable for producing cutlery?

Alloys and their properties

Which substances can react together to produce hydrogen gas?

The characteristic properties of acids and bases

Some observations on the reactions of the metals tin, lithium and manganese are given. What is the reactivity order of the three metals?

Reactivity series

What substances are needed for iron to rust?

Corrosion of metals

During the extraction of iron from hematite, Coke (carbon) and limestone are both raw materials. When each one is heated in the process, which type of reaction takes place?

Extraction of metals

Water is processed at a waterworks so that it becomes safe to drink. What is contained in the water as it leaves the waterworks?

Water

Which statement gives the description of a compound?

Elements, compounds and mixtures

The formulae for four compounds, W, X, Y and Z, are listed below. W: $\text{FeSO}_4$ X: $\text{(NH}_4)_3\text{PO}_4$ Y: $\text{KNO}_3$ Z: $\text{NaCl}$ Which of these compounds should be combined to make a fertiliser that provides the three elements needed for better plant growth?

Fertilisers

Certain combustion reactions release pollutant gases. Which of these reactions produce a pollutant gas that is absent from clean air?

Air quality and climate

Which row shows the homologous series that this molecular structure is part of?

Formulae, functional groups and terminology

Petroleum is separated by fractional distillation at an oil refinery. The table lists some fractions and their uses. 1 gasoline - ship fuel 2 refinery gas - for lubrication 3 naphtha - used to make chemicals 4 kerosene - as jet fuel Which rows match a correct use with the fraction named?

Fuels

What is the word equation for making ethanol?

Alcohols

Which row gives the properties of aqueous ethanoic acid?

The characteristic properties of acids and bases

Which row gives the correct comparison of the sizes of monomer and polymer molecules?

Polymers

$2.00\,\text{g}$ of powdered calcium carbonate is placed into $50.0\,\text{cm}^3$ of hydrochloric acid. Which apparatus should be used to measure these amounts of calcium carbonate and hydrochloric acid?

Experimental design

The diagram illustrates a chromatogram produced from the colours of three distinct sweets, X, Y and Z. How many separate red dyes are found in the sweets?

Chromatography

A mixture consists of sand and an aqueous solution of sodium chloride. Which processes would be used to separate out a sample of solid sand and a sample of solid sodium chloride from this mixture?

Separation and purification

Which statement concerning elements in the Periodic Table is correct?

Atomic structure and the Periodic Table

A student carries out tests on an unidentified compound M. The compound: - gives a lilac flame in a flame test - gives off a gas that turns limewater cloudy when dilute hydrochloric acid is added. What is M?

Identification of ions and gases

Which statement concerning ions and ionic bonds is true?

Ions and ionic bonds

Which molecule contains just two shared pairs of electrons?

Simple molecules and covalent bonds

Which statement about graphite accounts for its use as an electrode?

Giant covalent structures

Methane, $\text{CH}_4$, undergoes combustion in air, producing carbon dioxide and water. What balanced equation represents this reaction?

Fuels

Steam reacts with magnesium. $\text{Mg} + \text{H}_2\text{O} \rightarrow \text{MgO} + \text{H}_2$ If $2.43\,\text{g}$ of magnesium is allowed to react with an excess of steam, $4.03\,\text{g}$ of magnesium oxide and $0.20\,\text{g}$ of hydrogen are obtained. What is formed when $7.29\,\text{g}$ of magnesium reacts with an excess of steam?

The mole and the Avogadro constant

Substance M is a solid at $30\,^{\circ}\text{C}$. It is heated to $80\,^{\circ}\text{C}$, and its temperature is then recorded as it cools to room temperature. The cooling curve is shown. Between which times does substance M freeze?

Solids, liquids and gases

An electrolysis experiment is carried out with carbon electrodes. Hydrogen and oxygen are produced at the electrodes. What is the electrolyte?

Electrolysis

A concentrated aqueous copper(II) sulfate solution is electrolysed using copper electrodes. Which ionic half-equation shows the reaction occurring at the cathode?

Electrolysis

If powdered sodium carbonate is added to aqueous ethanoic acid, the temperature of the resulting mixture goes down. Which statement about this reaction is correct?

Exothermic and endothermic reactions

Magnesium powder reacts with an excess of dilute hydrochloric acid to form hydrogen gas. Which of the following statements about this reaction are correct?

The characteristic properties of acids and bases

The reaction between the aqueous compounds X and Y is slow and exothermic. The graph illustrates how the rate of this reaction varies over time. A student proposes that the reaction rate falls with time because:

Rate of reaction

Hydrogen combines with iodine to produce hydrogen iodide. $\text{H}_2(g) + \text{I}_2(g) \rightarrow 2\text{HI}(g)$ Which statements account for the reaction being faster when the pressure is raised, while the temperature remains constant?

Rate of reaction

Ammonium sulfate is used as a fertiliser. It is produced from ammonia and sulfuric acid. The ......1...... is produced by the ......2...... process, in which ......3...... is used as a catalyst. Which words fill gaps 1, 2 and 3?

Fertilisers

The reversible reaction shown occurs in a closed system at fixed temperature. $\text{P}(g) + \text{Q}(g) + \text{R}(g) \rightleftharpoons \text{S}(g) + \text{T}(g)$ Once the reaction has attained equilibrium, extra T is introduced. After T is added, which other substances have an increase in concentration?

Reversible reactions and equilibrium

In which equation is the underlined substance functioning as a reducing agent?

Redox

An aqueous solution is mixed with a solid. The products formed are an alkaline gas, a salt and water. What are the aqueous solution and the solid?

Identification of ions and gases

Which gas diffuses at the fastest rate?

Diffusion

Butanoic acid dissociates only to a limited extent in aqueous solution. Which row concerning butanoic acid is correct?

The characteristic properties of acids and bases

Copper(II) sulfate is made by reacting sulfuric acid with an excess of copper(II) carbonate. Why is copper(II) carbonate added in excess?

Preparation of salts

A section of the Periodic Table is shown. Which element has two electrons in its outer shell and three electron shells?

Atomic structure and the Periodic Table

The elements in Group I and Group II display similar patterns in their reactions with water and in density. Which row indicates how barium’s properties compare with those of calcium?

Arrangement of elements

Which two compounds contain the same transition element in two different oxidation states?

Transition elements

Which statement correctly describes brass?

Alloys and their properties

What is the symbol of the metal used to make aircraft because it has a low density?

Uses of metals

Which substances combine to produce hydrogen gas?

The characteristic properties of acids and bases

Coke (carbon) and limestone are two of the raw materials involved in extracting iron from hematite. Which reaction type takes place when each substance is heated during this process?

Extraction of metals

Certain combustion reactions give off pollutant gases. Which of the reactions form a pollutant gas that is absent from clean air?

Air quality and climate

Bromine has two stable isotopes. Isotope 1 has mass number $79$ and isotope 2 has mass number $81$. Which of the following statements is correct?

Isotopes

When one mole of alkane Y is completely burned in excess oxygen, it gives $72\,\text{dm}^3$ of carbon dioxide, measured at room temperature and pressure. What is Y?

Alkanes

The diagram shows the structure of organic compound X. What is X?

Naming organic compounds

What is the structural formula of the compound made when propene undergoes an addition reaction with bromine?

Alkenes

Ethanol is made on an industrial scale by fermentation and also by a catalysed addition reaction with steam. Which row describes one advantage of each process?

Alcohols

When carboxylic acids are heated with alcohols in the presence of an acid catalyst, what type of substance is produced in this reaction?

Carboxylic acids

Nylon is produced by condensation polymerisation. Which structure shows nylon?

Polymers

Which structure is the repeat unit of the addition polymer produced from but-1-ene?

Polymers

$2.00\,\text{g}$ of calcium carbonate powder is added to $50.0\,\text{cm}^3$ of hydrochloric acid. Which apparatus is used to measure these amounts of calcium carbonate and hydrochloric acid?

Experimental design

The diagram shows a chromatogram produced from the colours of three different sweets, X, Y and Z. How many different red dyes are found in the sweets?

Chromatography

A mixture consists of sand and an aqueous solution of sodium chloride. Which processes are used to obtain a sample of solid sand and a sample of solid sodium chloride from the mixture?

Separation and purification

Which statement about ions and ionic bonds is correct?

Ions and ionic bonds

A student carries out tests on an unknown compound M. The compound: - gives a lilac colour in a flame test - releases a gas that makes limewater turn cloudy when dilute hydrochloric acid is added. What is compound M?

Identification of ions and gases

A section of the Periodic Table is shown. Which type of chemical bonding is found in the oxide of F and in the oxide of G?

Arrangement of elements

Elements X and Y combine to make a compound. Element X loses two electrons, while element Y gains one electron. What charges do the ions of elements X and Y have, and what is the formula of the compound?

Ions and ionic bonds

Which statement concerning graphite accounts for its use as an electrode?

Giant covalent structures

Methane, $\text{CH}_4$, burns in air and produces carbon dioxide plus water. What is the balanced equation for this reaction?

Physical and chemical changes

The chemical equation for the thermal decomposition of sodium hydrogencarbonate is given as: $2\text{NaHCO}_3 \rightarrow \text{Na}_2\text{CO}_3 + \text{H}_2\text{O} + \text{CO}_2$. The $M_r$ of sodium hydrogencarbonate, $\text{NaHCO}_3$, is $84$. The $M_r$ of sodium carbonate, $\text{Na}_2\text{CO}_3$, is $106$. During an experiment, $2.1\,\text{g}$ of sodium hydrogencarbonate is heated, although only part of it decomposes. Every bit of the carbon dioxide is gathered and then measured at room temperature and pressure. The overall volume of carbon dioxide made is $0.21\,\text{dm}^3$. At room temperature and pressure, the volume occupied by $1$ mole of a gas is $24\,\text{dm}^3$. Which statement is correct?

The mole and the Avogadro constant

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.

Elements, compounds and mixtures

Draw a diagram of the filtration apparatus used to separate the soil from the solution formed after the soil is shaken with distilled water. On your diagram, label: the filtrate; the residue.

Water

This question concerns compounds containing nitrogen.

Oxides

This question focuses on metals and compounds of metals.

Transition elements

Potassium iodide is classified as an ionic compound.

Electrolysis

In Fig. 6.1, circle the alcohol functional group.

Alcohols

This question concerns iron.

Extraction of metals

A student looks at how iron powder reacts with dilute hydrochloric acid at 20 ^{\circ}C. The hydrochloric acid is in excess.

Rate of reaction

This question concerns gases present in clean, dry air and gases present in polluted air.

Air quality and climate

Lithium, sodium and potassium belong to Group I elements.

Group I properties

The Haber process is the method used to produce ammonia.

Reversible reactions and equilibrium

Copper is the element with atomic number 29 in the Periodic Table.

Transition elements

Propane, propene, propan-1-ol and propanoic acid belong to different homologous series, but each molecule contains three carbon atoms.

Carboxylic acids