May/June 2016

For which changes do the particles become more widely spaced? $\text{gas} \; \overset{W}{\underset{Y}{\rightleftharpoons}} \; \text{liquid} \; \overset{X}{\underset{Z}{\rightleftharpoons}} \; \text{solid}$

Solids, liquids and gases

The quantities of gases P and Q produced when substance X undergoes electrolysis are shown below. What is substance X?

Electrolysis

An energy level diagram for the reaction of sodium hydrogen carbonate with dilute hydrochloric acid is shown. Which row gives the correct description of the reaction type and the energy of the reactants and products?

Exothermic and endothermic reactions

The diagram illustrates several properties that substances can possess. Which labelled section of the diagram includes $^{235}\text{U}$?

Isotopes

A liquid X reacts with solid Y to produce a gas. Which two diagrams show appropriate methods for investigating the reaction rate (speed)?

Rate of reaction

In experiment S, hydrogen volume is measured when excess dilute sulfuric acid is added to zinc. A second experiment, T, uses the same mass of zinc but under different conditions. The outcomes of the two experiments are shown. Which changes in conditions between experiments S and T produce curve T?

Rate of reaction

The reaction between aluminium and iron(III) oxide is represented as follows: iron(III) oxide + aluminium $\rightarrow$ iron + aluminium oxide. Which of the following statements about this reaction is correct?

Reactivity series

Which reaction can be reversed?

Reversible reactions and equilibrium

Which statements are properties of an acid? 1 reacts with ammonium sulfate to produce ammonia 2 changes red litmus to blue

The characteristic properties of acids and bases

A section of the Periodic Table is shown. Which element produces an acidic oxide?

Oxides

The diagram illustrates a method for preparing copper(II) sulfate crystals. What are the functions of step 3 and step 4?

Preparation of salts

A sample of a dye is examined using chromatography. A line is marked across a strip of chromatography paper, and a spot of the dye is added to it. The paper is then put into water. Which row is the correct one?

Chromatography

The outcomes from two tests carried out on solid X are shown below. Test: aqueous sodium hydroxide added → observation: a green precipitate was produced. Test: acidified silver nitrate added → observation: a yellow precipitate was produced. What is X?

Identification of ions and gases

In which region of the Periodic Table is the metallic character of the elements greatest?

Arrangement of elements

The table gives some properties of four elements, P, Q, R and S. Two of these elements belong to Group I of the Periodic Table and the other two belong to Group VII. Which statement is correct?

Arrangement of elements

Which one of the following could be a transition element?

Transition elements

Two statements concerning argon are given. 1. Argon has a full outer shell of electrons. 2. Argon is very reactive and is used in lamps. Which is correct?

Noble gases

Three students, X, Y and Z, were informed that solid P reacts with dilute acids and also conducts electricity. The table lists the students’ suggestions for the identity of P.

Properties of metals

W, X and Y are metals; one of them is copper and another is iron. • W forms a coloured oxide that can be reduced by carbon. • X forms a black oxide and is also found in nature as an uncombined pure metal. • Y forms an oxide that cannot be reduced by carbon. Which metal is the most reactive, and what could W be?

Reactivity series

Tin is a metal that is less reactive than iron, and it is obtained from its ore cassiterite, $\text{SnO}_2$. Which of the following statements about tin are correct?

Extraction of metals

Which statement correctly describes the uses of metals?

Uses of metals

The diagram illustrates an experiment designed to find out how paint influences the rusting of iron. What change occurs in the water level in tubes P and Q?

Corrosion of metals

An experimental procedure includes the instruction below. Add $50\,\text{cm}^3$ of acid without delay. Which apparatus is most suitable to use?

Experimental design

A previously unknown planet has been found, and the gases in its atmosphere have been examined. The table gives the proportions of the gases in its atmosphere. Which gases are found in the planet’s atmosphere at a greater percentage than in Earth’s atmosphere?

Air quality and climate

Water was added to separate samples of anhydrous cobalt(II) chloride and anhydrous copper(II) sulfate. Which row shows the colour changes that occur in these reactions?

Transition elements

Which air pollutant has no effect on respiration?

Air quality and climate

The soil on a farm contains very little nitrogen (N) and phosphorus (P). Which fertiliser would raise the quality of this soil most effectively?

Fertilisers

If limestone is heated, it produces lime (calcium oxide) and carbon dioxide. $\text{CaCO}_3(s) \rightarrow \text{CaO}(s) + \text{CO}_2(g)$ Which statement is not correct?

Physical and chemical changes

The diagram illustrates how petroleum is separated into fractions. What might X, Y and Z stand for?

Fuels

Which of the compounds shown belong to the same homologous series?

Formulae, functional groups and terminology

Compound Q turns bromine water colourless. Each molecule of compound Q contains two carbon atoms. Which statement about compound Q is correct?

Alkenes

What substance is employed in making ethanol from ethene?

Alcohols

Ethene forms an addition polymer, as illustrated. Which terms are used to describe this polymer?

Polymers

Diamond and graphite are macromolecular substances. Which statement concerning diamond and graphite is incorrect?

Giant covalent structures

The diagram illustrates a molecule of the organic compound W. Which statement is incorrect?

Formulae, functional groups and terminology

The table gives the electronic structure of four atoms. W: 2,8,1 X: 2,8,4 Y: 2,8,7 Z: 2,8,8 Which pair of atoms would join together to make a covalent compound?

Simple molecules and covalent bonds

An aluminium atom has a nucleon number of $27$ and a proton number of $13$. How many neutrons are present in this aluminium atom?

Isotopes

What occurs when a bond is formed between a green gaseous element and a soft metallic element?

Ions and ionic bonds

The equation represents the reaction of magnesium with sulfuric acid. $\text{Mg} + \text{H}_2\text{SO}_4 \rightarrow \text{MgSO}_4 + \text{H}_2$ For this reaction, what mass of magnesium sulfate is produced when $6\,\text{g}$ of magnesium reacts with excess sulfuric acid?

The mole and the Avogadro constant

The diagram depicts an electrical cable. Which statement about the materials used is correct?

Properties of metals

During which changes do the particles become more widely spaced? gas $\rightleftharpoons$ liquid $\rightleftharpoons$ solid The changes are identified as follows: W: gas to liquid X: liquid to solid Y: liquid to gas Z: solid to liquid

Solids, liquids and gases

Which substances are formed at the electrodes when dilute sulfuric acid is electrolysed with inert electrodes?

Electrolysis

An energy level diagram for the reaction between magnesium and hydrochloric acid is shown. Which of the statements about the reaction is incorrect?

Exothermic and endothermic reactions

The diagram illustrates some properties that substances can possess. Which labelled section of the diagram includes $^{235}\text{U}$?

Isotopes

A liquid $X$ is reacted with solid $Y$ to produce a gas. Which two diagrams show appropriate methods for investigating the reaction rate (speed)?

Rate of reaction

The outcomes of two distinct reactions involving excess calcium carbonate and hydrochloric acid are shown. Which statement accounts for the differences between the reactions?

Rate of reaction

The equations shown below each represent redox reactions. $\text{Fe}_2\text{O}_3 + 3\text{CO} \rightarrow 2\text{Fe} + 3\text{CO}_2$ $2\text{ZnO} + \text{C} \rightarrow 2\text{Zn} + \text{CO}_2$ $\text{Fe}_2\text{O}_3 + 2\text{Al} \rightarrow \text{Al}_2\text{O}_3 + 2\text{Fe}$ $2\text{CO} + 2\text{NO} \rightarrow 2\text{CO}_2 + \text{N}_2$ In these reactions, which oxide is oxidised?

Redox

In which reaction does the colour change from blue to white?

Physical and chemical changes

Which statements describe the properties of an acid?

The characteristic properties of acids and bases

A section of the Periodic Table is displayed. Which element gives an acidic oxide?

Oxides

What is the correct order of steps used to prepare a pure sample of copper(II) sulfate crystals from copper(II) oxide and sulfuric acid?

Preparation of salts

In the chromatography experiment illustrated, which label indicates the solvent front?

Chromatography

These tests are performed on an aqueous solution of salt X. Sodium hydroxide solution is then added, producing a green precipitate that dissolves in excess. Next, a small piece of aluminium foil is introduced into the mixture and the mixture is heated; a gas is released that turns damp, red litmus paper blue. What is X?

Identification of ions and gases

At which location in the Periodic Table is the metallic character of the elements at its greatest?

Arrangement of elements

Rubidium belongs to Group I metals. Which statement concerning rubidium is incorrect?

Group I properties

The table provides details for four elements, P, Q, R and S, including melting point in $^\circ\text{C}$, electrical conductivity of the element when solid, density in $\text{g cm}^{-3}$, and the colour of the iodide of the element. Which elements could be transition elements?

Transition elements

A section of the Periodic Table is shown. Which element is a gas and does not make a compound with potassium?

Noble gases

Which property is not regarded as a typical metallic property?

Properties of metals

The table summarises some chemical properties of three metals W, X and Y, together with those of their oxides. It includes their reactions with steam, their reactions with dilute hydrochloric acid, and the reaction of each metal oxide with carbon. What is the order of reactivity of these metals, starting with the most reactive?

Reactivity series

In making steel, iron from a blast furnace is reacted with oxygen and calcium oxide. Which substances in the iron are taken out?

Extraction of metals

Copper is sometimes used for making cooking utensils. Three properties of copper are listed. Which of these properties make copper a suitable metal for cooking utensils?

Properties of metals

The diagram illustrates an experiment used to find out how paint influences the rusting of iron. What change occurs to the water level in tubes P and Q?

Corrosion of metals

One instruction in an experiment is given below. Add $50\ \text{cm}^3$ of acid quickly. Which piece of apparatus is most suitable to use?

Experimental design

A newly found planet has had its atmosphere analysed. The table gives the composition of its atmosphere: carbon dioxide $4\%$, nitrogen $72\%$, oxygen $24\%$. Which gases occur in the atmosphere of the planet at a greater percentage than they do in the Earth’s atmosphere?

Air quality and climate

Which of the following are tests used for water?

Water

Sulfur dioxide, carbon monoxide and oxides of nitrogen are widespread gaseous pollutants present in the air. Which pollutants are responsible for acid rain?

Air quality and climate

Which compound is not employed as a fertiliser?

Fertilisers

Lime (calcium oxide) is added to treat waste water produced by a factory. Which substance does the lime remove?

Water

The diagram illustrates how petroleum is separated into fractions. What might X, Y and Z stand for?

Fuels

Which compound does not belong to the alkane series, $\text{C}_n\text{H}_{2n+2}$?

Alkanes

A hydrocarbon W undergoes combustion to produce carbon dioxide and water. W also decolourises bromine water. What is the name of W, and what does its structure look like?

Alkenes

What term is used for the conversion of glucose into ethanol?

Alcohols

Ethene produces an addition polymer, as illustrated. Which terms are used to describe this polymer?

Polymers

Two statements about diamond are provided. 1. Diamond has a giant three-dimensional covalent structure made up of carbon atoms. 2. Diamond is among the hardest substances known. Which statement is correct?

Giant covalent structures

Which statement concerning carboxylic acids is incorrect?

Carboxylic acids

The table below gives the electronic structures of four atoms. W: $2,8,1$ X: $2,8,4$ Y: $2,8,7$ Z: $2,8,8$ Which pair of atoms joins together to make a covalent compound?

Simple molecules and covalent bonds

An atom of element Q has 19 electrons, 19 protons and 20 neutrons. Which element is Q?

Atomic structure and the Periodic Table

Lithium belongs to Group I of the Periodic Table. Nitrogen belongs to Group V of the Periodic Table. When lithium reacts with nitrogen, the ionic compound lithium nitride is formed. What happens to the electrons when lithium atoms and nitrogen atoms form ions?

Ions and ionic bonds

The equation below represents how magnesium reacts with sulfuric acid. $\text{Mg} + \text{H}_2\text{SO}_4 \rightarrow \text{MgSO}_4 + \text{H}_2$ For this reaction, what mass of magnesium sulfate is produced when $6\ \text{g}$ of magnesium is added to excess sulfuric acid? [$A_r$: H, 1; O, 16; Mg, 24; S, 32]

The mole and the Avogadro constant

The diagram illustrates an electrical cable. Which statement about the materials used is correct?

Properties of metals

During which changes do the particles become more widely spaced? $ \text{gas} \;\xrightleftharpoons[\;Y\;]{\;W\;}\; \text{liquid} \;\xrightleftharpoons[\;Z\;]{\;X\;}\; \text{solid} $

Solids, liquids and gases

Electricity is sent separately through concentrated hydrochloric acid, concentrated aqueous sodium chloride and dilute sulfuric acid. In which rows are the electrolysis products named correctly?

Electrolysis

The energy level diagram indicates the energies of the reactants and products in a chemical reaction. Which row gives the correct energy change and the type of reaction shown?

Exothermic and endothermic reactions

The diagram illustrates a number of properties that substances may possess. Which labelled section of the diagram includes $^{235}_{92}\text{U}$?

Isotopes

When liquid X reacts with solid Y, a gas is produced. Which two diagrams show suitable ways of investigating the rate (speed) of this reaction?

Rate of reaction

Magnesium is allowed to react with a dilute acid. The hydrogen gas produced is collected, and its volume is measured. The results are displayed on the graph. Between which times was the reaction fastest?

Rate of reaction

A highly vigorous reaction takes place when a mixture of chromium(III) oxide and aluminium is set alight using a magnesium fuse, as illustrated. The reaction equation is given below. $\text{Cr}_2\text{O}_3 + 2\text{Al} \rightarrow 2\text{Cr} + \text{Al}_2\text{O}_3$ Which substance is oxidised in the reaction?

Redox

The equations showing the reaction of water with anhydrous cobalt(II) chloride and anhydrous copper(II) sulfate are given below. $\text{CoCl}_2(s) + 6\text{H}_2\text{O}(l) \rightarrow \text{CoCl}_2\cdot6\text{H}_2\text{O}(s)$ $\text{CuSO}_4(s) + 5\text{H}_2\text{O}(l) \rightarrow \text{CuSO}_4\cdot5\text{H}_2\text{O}(s)$ Which statement is incorrect?

Ions and ionic bonds

Which statements describe properties of an acid?

The characteristic properties of acids and bases

A section of the Periodic Table is shown. Which element produces an acidic oxide?

Oxides

Salts may be prepared by reacting dilute hydrochloric acid with different substances. For which substance would any excess be impossible to remove by filtration?

Preparation of salts

Chromatography experiments are performed on four substances, P, Q, R and S. The same solvent is used for each experiment. The chromatograms produced are shown below. Which statement is incorrect?

Chromatography

A sample of solution containing substance X was tested, and the findings are given in the table below. flame test: lilac colour acidified silver nitrate solution added: yellow precipitate What is X?

Identification of ions and gases

In which part of the Periodic Table is the metallic character of the elements at its greatest?

Arrangement of elements

Which statement concerning the elements in Group I is correct?

Group I properties

Osmium belongs to the transition elements. Which row shows the properties you would expect for osmium?

Transition elements

Two statements concerning noble gases are provided. 1 Noble gases are reactive, monatomic gases. 2 Noble gases all have full outer shells of electrons. Which statement is correct?

Noble gases

A few characteristics of substance X are given below. • It allows electric current to pass through it only when it is molten. • It has a very high melting point. • It reacts with oxygen on burning, and the product then dissolves in water to form a solution with $\text{pH }11$. What is X?

Ions and ionic bonds

The sequence below gives the reactivity order for some elements. $\text{K} \; \text{Na} \; \text{Ca} \; \text{Mg} \; \text{Zn} \; \text{Fe} \; (\text{H}) \; \text{Cu}$ Which of the following statements about the reactivity of these metals is correct?

Reactivity series

Iron is extracted from its ore in a blast furnace and then used to produce steel. Iron taken from the blast furnace contains ......1...... as an impurity. To remove this impurity, ......2...... is blown through the molten iron. ......3...... is also added so that the oxides of phosphorus and silicon are removed, as these are ......4...... . Which words complete the sentences about the conversion of iron to steel?

Extraction of metals

Copper is a transition element used in the manufacture of saucepans. Which property does not apply to copper?

Properties of metals

The diagram illustrates an experiment used to investigate the way paint affects the rusting of iron. What happens to the water level in tubes P and Q?

Corrosion of metals

An instruction for an experiment states the following. Add $50\,\text{cm}^3$ of acid as quickly as possible. Which apparatus would be most suitable to use?

Experimental design

A newly found planet has had its atmosphere analysed. The table gives the make-up of its atmosphere. carbon dioxide: $4\%$ nitrogen: $72\%$ oxygen: $24\%$ Which gases occur in the planet’s atmosphere at a greater percentage than in Earth’s atmosphere?

Air quality and climate

When petrol is burnt inside a car engine, the substances below may be produced. Which substance is chiefly responsible for acid rain?

Air quality and climate

Which of the following statements about methane is incorrect?

Alkanes

The formulae for four compounds, W, X, Y and Z, are shown. Which combination of compounds forms a complete fertiliser?

Fertilisers

What process is used to produce lime (calcium oxide) from limestone (calcium carbonate)?

Physical and chemical changes

The diagram illustrates how petroleum is separated into fractions. What might X, Y and Z stand for?

Separation and purification

Which compound is not part of the same homologous series as the other three compounds?

Formulae, functional groups and terminology

What reaction is used to test for alkenes?

Alkenes

Which statement concerning ethanol is correct?

Alcohols

Ethene produces an addition polymer, as shown. Which words are used to describe this polymer?

Polymers

The structures of diamond and graphite are shown. Which statement about diamond and graphite is incorrect?

Giant covalent structures

When liquid W undergoes complete combustion, it produces carbon dioxide and water. Liquid W is a compound made from carbon, hydrogen and oxygen. An aqueous solution of liquid W has $\text{pH}~7$. What is liquid W?

Alcohols

The table presents the electronic structures of four atoms. W: $2,8,1$ X: $2,8,4$ Y: $2,8,7$ Z: $2,8,8$ Which two atoms join together to make a covalent compound?

Simple molecules and covalent bonds

The table gives the atomic structure of four atoms. Which atom is not a metal?

Atomic structure and the Periodic Table

Potassium, K, combines with fluorine, F, to make a compound. Which of the following statements about this compound are correct?

Ions and ionic bonds

The equation represents the reaction of magnesium with sulfuric acid. $\text{Mg} + \text{H}_2\text{SO}_4 \rightarrow \text{MgSO}_4 + \text{H}_2$ For this reaction, what mass of magnesium sulfate is produced when $6\,\text{g}$ of magnesium reacts with excess sulfuric acid?

The mole and the Avogadro constant

The diagram illustrates an electrical cable. Which statement about the materials used is correct?

Properties of metals