Feb/March 2020

Which row shows the particles of a gas colliding the most often?

Solids, liquids and gases

Which energy level diagram represents the reaction that releases the greatest amount of energy?

Exothermic and endothermic reactions

Which change counts as a physical change?

Physical and chemical changes

Marble chips (calcium carbonate) undergo reaction with hydrochloric acid in an exothermic reaction. $\text{calcium carbonate} + \text{hydrochloric acid} \rightarrow \text{calcium chloride} + \text{water} + \text{carbon dioxide}$ If excess marble chips are placed into dilute hydrochloric acid, the reaction begins rapidly, then becomes slower until it comes to a stop. Why does the reaction rate become slower?

Rate of reaction

The diagram illustrates the transformation of an anhydrous salt into its hydrated form. Which statement is correct?

Physical and chemical changes

A vigorous reaction takes place when a mixture of chromium(III) oxide and aluminium is ignited using a magnesium fuse, as illustrated. The equation for the reaction 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 soil on a farm is acidic. Which substance should the farmer apply in order to neutralise the soil?

The characteristic properties of acids and bases

Three elements, X, Y and Z, are burnt in oxygen. The oxides that form are dissolved in water and the pH of the resulting solutions is measured. Which of the following statements are correct?

Oxides

These substances may be combined to make salts. In which reactions can the surplus reactant be removed from the solution by filtration?

Preparation of salts

Salt S is dissolved in water, and three tests are performed on the solution. Identify S.

Identification of ions and gases

Which statement concerning the Periodic Table is correct?

Arrangement of elements

Which test is used to demonstrate that a water sample is pure?

Water

The diagram displays elements W, X, Y and Z in part of the Periodic Table. Which statement about the reactivity of these elements is correct?

Arrangement of elements

The properties of some substances are given. 1 They allow electricity to pass through them. 2 Their densities are low. 3 They melt at high temperatures. 4 They can be hammered into shape. Which of these properties are shown by transition metals?

Transition elements

Which statement concerning the noble gas argon is correct?

Noble gases

Sodium belongs to Group I of the periodic table. Which property, common to most metals, is not exhibited by sodium?

Properties of metals

Manganese, nickel and silver are metals. Samples of powdered manganese, nickel and silver were put into separate test-tubes of dilute hydrochloric acid. The observations are shown. What is the order of reactivity of the metals, from most reactive to least reactive?

Reactivity series

Which of the following statements about aluminium is correct?

Properties of metals

Some properties of aluminium are given below. 1 It conducts heat. 2 It has a low density. 3 It is strong. 4 It is resistant to corrosion. Which of these properties make aluminium suitable for producing food containers for chilled food products?

Properties 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

Sulfur dioxide, carbon monoxide and oxides of nitrogen are common gaseous pollutants present in the atmosphere. Which pollutants play a part in acid rain formation?

Air quality and climate

What methods can be used to prevent iron from rusting?

Corrosion of metals

Which apparatus would be used to measure $1.5\text{ cm}^3$ of a solution accurately?

Experimental design

Fertilisers are blends of various compounds that are used to promote crop growth. Which pair of substances includes the three essential elements needed for plant growth?

Fertilisers

Which process does not release a greenhouse gas into the atmosphere?

Air quality and climate

For what reason is sulfur dioxide used as a food preservative?

Oxides

Which of the following statements about lime (calcium oxide) and limestone (calcium carbonate) are correct?

Elements, compounds and mixtures

The structural formulae of two organic compounds, P and Q, are given below. P: $\text{CH}_3\text{CH}_2\text{CH}_2\text{OH}$ Q: $\text{CH}_3\text{CH} = \text{CHCH}_3$ What class of organic compounds do P and Q belong to?

Formulae, functional groups and terminology

Petroleum is a crucial raw material that can be split into useful products. Which terms are used to describe petroleum and the method used to separate it?

Separation and purification

What kind of compound belongs to a homologous series?

Formulae, functional groups and terminology

Which of the following statements about propene are correct?

Alkenes

Which row gives details of how ethanol is produced and what its properties are?

Alcohols

Which of the statements below concerning ethanoic acid are correct?

Carboxylic acids

An atom is represented below. What is the nucleon number of this atom?

Atomic structure and the Periodic Table

Which of these polymers are natural polymers?

Polymers

Lithium combines with fluorine to produce the compound lithium fluoride. Which statement about this reaction is correct?

Ions and ionic bonds

Ammonia, $\text{NH}_3$, is a covalent molecule. Which diagram represents the arrangement of outer-shell electrons in an ammonia molecule?

Simple molecules and covalent bonds

Which row gives the structure and one use of diamond?

Giant covalent structures

Methane, $\text{CH}_4$, reacts with air to produce carbon dioxide and water. What balanced equation represents this reaction?

Formulae

Which statement regarding electrolysis is correct?

Electrolysis

The formula for methane is $\text{CH}_4$ and the formula for ethane is $\text{C}_2\text{H}_6$. Which row gives the definition of diffusion and compares the relative rates of diffusion for methane and ethane?

Diffusion

Which of the following statements concerning the electrolysis of molten lead(II) bromide are correct?

Electrolysis

An aqueous solution of copper(II) sulfate is electrolysed with carbon electrodes. Which statement is correct?

Electrolysis

Nitrogen trifluoride, $\text{NF}_3$, is employed in the production of some kinds of solar panels. The equation for the formation of nitrogen trifluoride is shown: $\text{N}_2 + 3\text{F}_2 \rightarrow 2\text{NF}_3$. Using the table of bond energies, what energy change does this reaction have?

Exothermic and endothermic reactions

Which of the following statements about hydrogen fuel cells are correct?

Hydrogen–oxygen fuel cells

Which change counts as a physical change?

Physical and chemical changes

A student places excess magnesium ribbon into $10\text{ cm}^3$ of $0.5\ \text{mol dm}^{-3}$ sulfuric acid. The hydrogen gas is collected, and its volume is recorded at intervals of 10 seconds. The experiment is then carried out again with the same mass of magnesium ribbon, but this time $5\text{ cm}^3$ of $0.5\ \text{mol dm}^{-3}$ sulfuric acid is mixed with $5\text{ cm}^3$ of water. Which graph shows the results of the second experiment?

Rate of reaction

An equilibrium equation is given: $\text{N}_2\text{O}_4(\text{g}) \rightleftharpoons 2\text{NO}_2(\text{g})$. The forward reaction absorbs heat. How do temperature and pressure changes affect the equilibrium position?

Reversible reactions and equilibrium

In which reaction does the underlined compound act as a reducing agent?

Redox

X, Y and Z are oxides of elements in the same period of the Periodic Table. Some details about each oxide are given. Which type of oxide is X, which type is Y and which type is Z?

Oxides

Four different acids have been dissolved in water. Which beaker contains the strong acid solution with the greatest concentration?

The characteristic properties of acids and bases

What test is used to show that a water sample is pure?

Water

The substances below may be combined to make salts. In which reactions may the excess reagent be removed from the solution through filtration?

Preparation of salts

Salt S is dissolved in water, after which the solution is subjected to three tests. Which substance is S?

Identification of ions and gases

Which statement concerning the Periodic Table is correct?

Arrangement of elements

The diagram illustrates elements W, X, Y and Z in part of the Periodic Table. Which statement about the elements’ reactivity is correct?

Arrangement of elements

Several properties of substances are listed. Which of these properties are displayed by transition metals?

Transition elements

Sodium is a Group I metal. Which property, which is characteristic of most metals, is not displayed by sodium?

Properties of metals

Iron, copper, magnesium and Y are each heated on their own with their oxides. The outcomes are displayed. In what order are the metals arranged by reactivity, starting with the least reactive?

Reactivity series

Aluminium is produced from bauxite by electrolysis. Which statement is correct?

Extraction of metals

A list shows several properties of aluminium. Which of these properties mean aluminium is suitable for making food containers for chilled food products?

Uses of metals

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

Water

Chromatography is used to separate and identify the components of mixtures that are coloured as well as those that are colourless. When the mixture is colourless, the chromatogram must be treated with another chemical. What is the name of this kind of chemical?

Chromatography

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

Air quality and climate

In petrol engines of cars, oxides of nitrogen such as NO and NO$_2$ are produced. The car’s catalytic converter removes them from the exhaust gases by means of reactions. Which row shows how oxides of nitrogen are produced in a petrol engine, and a reaction taking place in the catalytic converter?

Air quality and climate

Zinc is applied to iron as a protective coating to stop rusting. Why is zinc a suitable metal to use?

Corrosion of metals

Fertilisers are blends of various compounds that are used to boost crop growth. Which pair of substances contains the three essential elements needed for plant growth?

Fertilisers

Which row gives the conditions employed in the production of sulfuric acid using the Contact process?

Preparation of salts

Petroleum is an important raw material that can be separated into useful products. Which terms are used to describe petroleum and the method used to separate it?

Separation and purification

Which of the following statements about propene are correct?

Alkenes

Which row gives the description of ethanol production and its properties?

Alcohols

Ethanoic acid is a typical carboxylic acid. Which statement concerning ethanoic acid is correct?

Carboxylic acids

Which structure shows the ester produced from ethanoic acid and propanol?

Formulae, functional groups and terminology

Lithium combines with fluorine to produce the compound lithium fluoride. Which statement about this reaction is correct?

Ions and ionic bonds

A polymer structure is shown. Which of the following statements about the polymer are correct?

Polymers

$^{14}_{6}\text{C}$ and $^{12}_{6}\text{C}$ are isotopes of carbon. Which statement correctly describes these isotopes?

Isotopes

The molecular structure of hydrazine, $\text{N}_2\text{H}_4$, is shown. Which statement about the bonding in hydrazine is incorrect?

Simple molecules and covalent bonds

Solid X has a high boiling point. It consists of positive ions surrounded by a sea of electrons. What other properties does solid X have?

Metallic bonding

Some ions have their formulae shown. In which row is the formula incorrect?

Ions and ionic bonds

The decomposition equation for magnesium nitrate is shown below. $2\text{Mg(NO}_3)_2\text{(s)} \rightarrow 2\text{MgO(s)} + 4\text{NO}_2\text{(g)} + \text{O}_2\text{(g)}$. What volume of gas is formed when $0.1$ moles of magnesium nitrate are decomposed completely?

The mole and the Avogadro constant

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.

Elements, compounds and mixtures

Iron is obtained by heating iron ore, limestone and coke (carbon) together in air inside a blast furnace. A diagram of the blast furnace is shown.

Extraction of metals

Water is vital in many industrial processes.

Water

Angelic acid and ethanoic acid are each carboxylic acids, and the structure of angelic acid is shown here.

Carboxylic acids

The table presents some properties of four metals from Group I of the Periodic Table.

Group I properties

This question concerns the reactions of magnesium with nitric acid.

Rate of reaction

Electrolysis of dilute sulfuric acid generates gases at both electrodes.

Electrolysis

The structural diagrams of four substances, C, D, E and F, are shown.

Group VII properties

Petroleum is a valuable natural resource. The diagram illustrates how petroleum may be separated into useful substances. The diagram labels the fractions in order from the top down as follows: refinery gas, gasoline fraction, A, kerosene fraction, diesel oil, fuel oil fraction, lubricating oil fraction, with petroleum entering near the bottom and B leaving at the bottom.

Fuels

Aluminium is obtained from its ore. The ore is first changed into pure aluminium oxide, and electrolysis is then carried out as shown. The diagram labels: power supply (+ and -), anodes, wires, cathode, electrolyte, and molten aluminium.

Extraction of metals

The Periodic Table is a way of sorting elements into groups.

Atomic structure and the Periodic Table

Iron is a representative transition element. Iron: • functions as a catalyst • produces coloured compounds • shows more than one oxidation state.

Transition elements

Polymers are classified into two types.

Polymers