Feb/March 2018

The four physical changes below are given. 1 condensation 2 evaporation 3 freezing 4 sublimation For which of these changes do the particles become farther apart?

Solids, liquids and gases

Statement 1: Hydrogen serves as a fuel. Statement 2: As hydrogen burns in air and forms water, heat energy is released. Which statement is correct?

Fuels

The diagram shows a match. When the match is struck, a chemical reaction occurs. Which row gives the description of the chemical reaction?

Exothermic and endothermic reactions

Magnesium carbonate was mixed with dilute hydrochloric acid in a conical flask. The conical flask was set on a balance, and the mass of the conical flask and its contents was measured as the reaction continued. As the reaction took place, carbon dioxide gas was given off. The reaction was carried out at two different temperatures. Which row is correct?

Rate of reaction

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?

Elements, compounds and mixtures

In which equation does the underlined substance undergo oxidation?

Redox

What property is displayed by sodium hydroxide, an alkali?

The characteristic properties of acids and bases

When a solution of compound Z is mixed with aqueous ammonia, a light blue precipitate is formed. This precipitate dissolves in excess of ammonia. A flame test is then carried out on compound Z. What colour is the flame?

Identification of ions and gases

Carbon, copper, magnesium, sodium and sulfur are each able to form oxides. How many of these elements produce acidic oxides?

Oxides

Which method is employed to prepare the salt copper(II) sulfate?

Preparation of salts

The Periodic Table contains every known element. Elements are arranged in order of ...... 1 ...... number. The melting points of Group I elements ...... 2 ...... down the group. The melting points of Group VII elements ...... 3 ...... down the group. Which words correctly fill gaps 1, 2 and 3?

Arrangement of elements

The diagram displays liquid in a burette and a measuring cylinder. Which row gives the readings for the burette and the measuring cylinder?

Experimental design

Which of the following statements about Group I and Group VII elements is correct?

Group I properties

Which statement gives a description of transition elements?

Transition elements

What trend is observed across the period from sodium to argon?

Arrangement of elements

For what reason is argon used in lamps?

Noble gases

Metals W, X, Y and Z are each treated with dilute hydrochloric acid. The oxides of metals W, X, Y and Z are then heated in the presence of carbon. The outcomes are shown. What order are the metals in, from most reactive to least reactive?

Reactivity series

Iron is obtained from $\text{Fe}_2\text{O}_3$ by reducing it with carbon. It is hard to extract aluminium from $\text{Al}_2\text{O}_3$. Electrolysis is required for this process. Beginning with the most reactive, which reactivity order is correct?

Reactivity series

Which two features are physical properties common to all pure metals?

Properties of metals

Which statement concerning the uses of aluminium, copper and iron is correct?

Uses of metals

The list shows four experiments involving calcium carbonate. 1 acid added 2 alkali added 3 heated strongly 4 water added Which experiments released carbon dioxide?

The characteristic properties of acids and bases

Water has to be treated before it becomes suitable for household use. Which processes are used to remove suspended solids and to destroy bacteria?

Water

Substance L has a melting point of $-7\,^{\circ}\text{C}$ and appears as a brown liquid at room temperature. Which temperature gives the boiling point of pure L?

Solids, liquids and gases

Which gas is absent from clean air?

Air quality and climate

Which two compounds would be used to make an NPK fertiliser?

Fertilisers

During the decomposition of vegetation, which pollutant gas is released?

Air quality and climate

Sulfur can be burned to form sulfur dioxide. Which row gives a source of sulfur and a use of sulfur dioxide?

Oxides

The diagram gives the pH readings for the soil in two sections of a garden, X and Y. X: $\text{pH }7.0$ Y: $\text{pH }5.5$ Lime is applied to neutralise the soil in one section of the garden. Which section of the garden should receive the lime, and what is the reason?

The characteristic properties of acids and bases

Which substance is not used as fuel?

Fuels

Which molecular formula is that of an alkene?

Alkenes

Three chemical reactions are listed. 1 the catalytic addition of steam to ethene 2 the combustion of ethanol 3 the fermentation of glucose In which reaction does the relative molecular mass of the carbon-containing compound fall?

Relative masses of atoms and molecules

How is ethanol made by fermentation?

Alcohols

A compound has the formula $\text{CH}_3\text{COOH}$. Which of the following is not a property of this compound?

Carboxylic acids

A student is provided with a mixture containing barium sulfate, copper(II) sulfate and water. The table gives details about barium sulfate and copper(II) sulfate. How does the student obtain copper(II) sulfate crystals from the mixture?

Separation and purification

Which statement about polymers is correct?

Polymers

What is meant by the nucleon number of an atom?

Atomic structure and the Periodic Table

Caesium, Cs, is an element in Group I of the Periodic Table. When caesium reacts, it produces a positive ion, $\text{Cs}^+$. How does a caesium ion form?

Ions and ionic bonds

Which of the following statements about graphite and diamond is correct?

Giant covalent structures

What does the term relative atomic mass, $A_r$, mean?

Relative masses of atoms and molecules

Which of the following statements about electrolysis reactions is correct?

Electrolysis

Hydrogen chloride gas, $\text{HCl}$, reacts with ammonia gas, $\text{NH}_3$, to produce solid ammonium chloride. The apparatus is arranged as shown. After a few minutes, solid ammonium chloride appears at the point where the two gases meet. The experiment is repeated with hydrogen bromide, $\text{HBr}$, used instead of hydrogen chloride. At what distance along the tube does solid ammonium bromide form?

Diffusion

Two metals are joined together to form a simple cell, as illustrated. The table gives the voltmeter reading when different metals are used. If metal 2 is more reactive than metal 1, the measured voltage is positive. The larger the difference in the reactivity of the metals, the bigger the voltmeter reading. What is the order of reactivity?

Reactivity series

The energy level diagram for the reaction of $X_2(g)$ with $Y_2(g)$ to produce $XY$ gas is shown. Which statement is correct?

Exothermic and endothermic reactions

Methane reacts with oxygen to produce carbon dioxide and water. $\text{CH}_4 + 2\text{O}_2 \rightarrow \text{CO}_2 + 2\text{H}_2\text{O}$ The bond energies are listed in the table below. What is the energy change for this reaction?

Exothermic and endothermic reactions

Methanol is formed when carbon monoxide reacts with hydrogen. This reaction is reversible. $\text{CO}(g) + 2\text{H}_2(g) \rightleftharpoons \text{CH}_3\text{OH}(g)$ The forward reaction releases heat. Which combination of temperature and pressure results in the greatest equilibrium yield of methanol?

Reversible reactions and equilibrium

The ionic equation for the reaction between zinc and aqueous copper ions is given below. $\text{Zn}(s) + \text{Cu}^{2+}(aq) \rightarrow \text{Zn}^{2+}(aq) + \text{Cu}(s)$ Which statement about this reaction is correct?

Redox

In which reaction is the reaction rate unaffected by light?

Rate of reaction

When calcium carbonate is added to dilute hydrochloric acid, bubbles of carbon dioxide are produced. If the temperature is raised, this reaction happens more quickly. Which row gives the correct explanation for this observation?

Rate of reaction

An acidic solution is formed when ethanoic acid reacts with water. Which row shows the functions of ethanoic acid and water in this reaction?

The characteristic properties of acids and bases

When a solution of compound Z is treated with aqueous ammonia, a pale blue precipitate forms. This precipitate then dissolves in excess ammonia. A flame test is carried out on compound Z. What colour is the flame?

Identification of ions and gases

Carbon, copper, magnesium, sodium and sulfur are all able to make oxides. How many of these elements make acidic oxides?

Oxides

At room temperature, substance L is a brown liquid, and its melting point is $-7\,^{\circ}\text{C}$. Which temperature corresponds to the boiling point of pure L?

Solids, liquids and gases

Which method is used to prepare the salt copper(II) sulfate?

Preparation of salts

The Periodic Table displays every element that is known. The elements are arranged in ...... 1 ...... number order. The melting points of Group I elements ...... 2 ...... as you move down the group. The melting points of Group VII elements ...... 3 ...... as you move down the group. Which words correctly fill gaps 1, 2 and 3?

Arrangement of elements

Metal X reacts with non-metal Y to produce an ionic compound whose formula is $X_2Y$. Which of the statements are correct?

Ions and ionic bonds

Which of the following statements about Group I and Group VII elements are correct?

Group I properties

Which two characteristics are physical properties of all pure metals?

Properties of metals

Aluminium is obtained from aluminium oxide by electrolysis. Carbon dioxide is produced in this process. Which equation represents the production of carbon dioxide during the extraction of aluminium from aluminium oxide by electrolysis?

Electrolysis

A portion of solid X was placed into three separate solutions in order to estimate where X sits in the reactivity series. $X(s) + \text{FeSO}_4(aq) \rightarrow$ no reaction $X(s) + 2\text{HCl}(aq) \rightarrow X\text{Cl}_2(aq) + \text{H}_2(g)$ $X(s) + \text{Zn(NO}_3)_2(aq) \rightarrow$ no reaction Which other solution would react with solid X?

Reactivity series

Which statement concerning the uses of aluminium, copper and iron is correct?

Uses of metals

Air consists of a mixture of gases. The melting and boiling points of several gases found in clean, dry air are given. During the fractional distillation of liquid air, which gas is the first to boil?

Separation and purification

Water has to be purified before it can be used safely in the home. Which processes are used to remove solid impurities and to kill bacteria?

Water

Chromatography is carried out on a mixture that contains a drug. The drug has an $R_f$ value of $0.66$. The diagram is not drawn to scale. Which spot on the chromatogram shows the drug?

Chromatography

Which processes do not release carbon dioxide?

Air quality and climate

Which two compounds would be used to produce an NPK fertiliser?

Fertilisers

What pollutant gas is released during the decomposition of vegetation?

Air quality and climate

The reaction equation for making sulfur trioxide from sulfur dioxide is shown below. $2\text{SO}_2(g) + \text{O}_2(g) \rightleftharpoons 2\text{SO}_3(g)$ The forward reaction releases heat. Which pairing of pressure and temperature gives the greatest equilibrium yield of sulfur trioxide?

Reversible reactions and equilibrium

The diagram indicates the pH readings for the soil in two sections of a garden, X and Y. X has pH $7.0$. Y has pH $5.5$. Lime is applied to neutralise the soil in one section of the garden. Which section of the garden should receive the lime, and why?

The characteristic properties of acids and bases

Statement 1: Hydrogen is used as a fuel. Statement 2: As hydrogen burns in air and forms water, heat energy is released. Which statement is correct?

Exothermic and endothermic reactions

Which row shows compounds that belong to the same homologous series?

Formulae, functional groups and terminology

Three chemical reactions are depicted. 1. catalytic addition of steam to ethene 2. combustion of ethanol 3. fermentation of glucose In which of these reactions does the relative molecular mass of the carbon-containing compound fall?

Alkenes

By what process is ethanol produced through fermentation?

Alcohols

Which substances combine to produce ethyl propanoate?

Carboxylic acids

Caesium, $\text{Cs}$, is a Group I element in the Periodic Table. When caesium reacts, it produces the positive ion, $\text{Cs}^+$. In what way is a caesium ion formed?

Ions and ionic bonds

The structure of a chlorofluorocarbon polymer is shown. Which monomer is used in the formation of this polymer?

Polymers

Copper is described as a lattice made up of positive ions surrounded by a ‘sea of electrons’. Which of the following statements are correct?

Metallic bonding

Three claims about diamond, graphite and silicon(IV) oxide are given. Which claims are correct?

Giant covalent structures

A hydrochloric acid solution has a concentration of $0.5\,\text{mol dm}^{-3}$. What amount, in moles, of hydrochloric acid is contained in $25\,\text{cm}^3$ of this solution?

The mole and the Avogadro constant

A sample of an iron oxide contains $50.4\,\text{g}$ of iron and $21.6\,\text{g}$ of oxygen. Determine the empirical formula of the iron oxide.

Formulae

A solution of copper(II) sulfate may be electrolysed with either copper electrodes or carbon electrodes. Which of the following statements are correct?

Electrolysis

The diagrams show the structures of five substances, A, B, C, D and E. A contains an ionic lattice with Na⁺ and Br⁻ ions arranged in alternating positions. B is a molecule in which two carbon atoms are bonded to each other, and each carbon is also bonded to hydrogen and bromine atoms. C represents O=C=O. D has a central iodine atom joined to three chlorine atoms. E represents O=O. Use only the substances shown in the diagram to answer the questions below. A substance may be chosen once, more than once or not chosen at all.

Isotopes

The table gives the mass of each ion type in a 100 cm^{3} milk sample.

Identification of ions and gases

Explain these observations using the kinetic particle model.

Group VII properties

Which two statements about members of a homologous series are true? Tick two boxes. Their chemical properties are similar. Their physical properties are similar. They share the same functional group. Their relative molecular masses are identical. They contain the same number of carbon atoms.

Formulae, functional groups and terminology

What feature of the diagram indicates that molten magnesium has a lower density than molten magnesium chloride?

Electrolysis

State the name of the hydrocarbon found in the highest concentration in natural gas.

Air quality and climate

Describe the reactions of hydrochloric acid with: - calcium oxide - magnesium - a named acid-base indicator of your choice.

The characteristic properties of acids and bases

Hydrochloric acid with a concentration of 1.2 mol/dm^{3} is used, while every other condition stays unchanged.

Reactivity series

This question concerns gases.

Solids, liquids and gases

Sodium chloride is a standard example of an ionic compound.

Electrolysis

Limestone rock is composed mainly of calcium carbonate, CaCO$_3$.

The characteristic properties of acids and bases

Ammonia is a significant chemical substance.

The characteristic properties of acids and bases

Alcohols form a homologous series of organic compounds that share the same general formula.

Alcohols