Oct/Nov 2020

The gradual movement of a substance from a region of high concentration to one of low concentration. Which process is described here?

Diffusion

What statement explains why graphite is used as a lubricant?

Giant covalent structures

The equation for the combustion of propane in air is given below. $\text{C}_3\text{H}_8(\text{g}) + x\text{O}_2(\text{g}) \rightarrow 3\text{CO}_2(\text{g}) + y\text{H}_2\text{O}(\text{g})$. What values of $x$ and $y$ make the equation balanced?

Formulae

The relative atomic mass of chlorine is 35.5. In a calculation of relative atomic mass, the mass of a chlorine atom is compared with the mass of which particle?

Relative masses of atoms and molecules

A concentrated aqueous solution of sodium chloride is electrolysed using platinum electrodes. What is the main product produced at each electrode?

Electrolysis

Three substances are shown below. 1 copper 2 dilute sulfuric acid 3 solid lead(II) bromide Which of these substances conduct electricity?

Electrolysis

Sodium nitrate is put into water in a beaker and the mixture is stirred until it dissolves. When the experiment is finished, the beaker feels cold. Which row shows the reaction?

Exothermic and endothermic reactions

Which substance does not need oxygen to release energy?

Fuels

Which process is associated with a physical change?

Physical and chemical changes

A sign on display in a flour mill is pictured. Which statement explains why there is a risk of explosion in a flour mill?

Rate of reaction

The graph presents the outcomes of two experiments that investigate the rate of reaction between excess calcium carbonate and dilute hydrochloric acid. In each experiment, the volume of carbon dioxide released is recorded at fixed time intervals. Which statement describes the difference in conditions between experiments 1 and 2?

Rate of reaction

What happens to the average speed of gas particles when pressure and temperature both increase?

Solids, liquids and gases

On heating pink crystals of cobalt(II) chloride, water vapour is released and the colour of the solid turns blue. $\text{CoCl}_2\cdot6\text{H}_2\text{O} \rightleftharpoons \text{CoCl}_2 + 6\text{H}_2\text{O}$ What change occurs when water is added to the blue solid?

Reversible reactions and equilibrium

During which reaction is the sulfur, S, in sulfur(I) oxide, $\text{S}_2\text{O}$, reduced?

Redox

Which property is typical of acids?

The characteristic properties of acids and bases

There are four separate sets of oxides. 1 $\text{MgO}$ $\text{FeO}$ $\text{CuO}$ 2 $\text{CaO}$ $\text{SO}_2$ $\text{TiO}_2$ 3 $\text{PbO}$ $\text{CaO}$ $\text{Cl}_2\text{O}$ 4 $\text{NO}_2$ $\text{Br}_2\text{O}$ $\text{P}_2\text{O}_5$ Which of the following statements about these oxides is correct?

Oxides

A student performs an experiment to make pure magnesium sulfate crystals. The diagram illustrates the initial stage of the preparation. He adds magnesium carbonate until no further reaction occurs. Which process should he use for the following stage?

Preparation of salts

Which ion gives a green precipitate when aqueous sodium hydroxide is added?

Identification of ions and gases

The locations of four elements in the Periodic Table are shown. Which element is a gas that can displace iodine from sodium iodide?

Group VII properties

A flammable gas has to be taken out of a tank at an industrial plant. To keep this safe, an inert gas is used. Which gas would be suitable?

Noble gases

A substance called X has these properties. 1. It has a very high melting point. 2. It conducts electricity when it is solid and when it is liquid. 3. It is malleable. 4. It has a large density. Which substance is X?

Properties of metals

A reactivity series is displayed. sodium calcium magnesium carbon zinc iron hydrogen copper Which statement is correct?

Reactivity series

Which piece of apparatus is able to measure only one fixed volume?

Experimental design

What is the symbol for the metal that is used to make aircraft because it is strong and has a low density?

Uses of metals

Oxides of nitrogen are released from car exhausts. Which row most accurately indicates why oxides of nitrogen are undesirable in the atmosphere?

Air quality and climate

Both reactions, M and N, produce carbon dioxide. M: $\text{CaCO}_3 \rightarrow \text{CO}_2$ N: $\text{CH}_4 \rightarrow \text{CO}_2$ What are the reaction types for M and N?

Physical and chemical changes

Which row shows two applications of sulfur dioxide?

Oxides

Which statement concerning lime and limestone is correct?

Elements, compounds and mixtures

Which compound has a chemical name that finishes with -ol?

Alcohols

Petroleum is divided into fractions by fractional distillation. The separation takes place in a fractionating column. Some properties of three of these fractions are given below. Fraction 1: the molecules contain $5\text{-}10$ carbon atoms. Fraction 2: boiling point range $320\text{-}350\,^\circ\text{C}$, the molecules contain $16\text{-}24$ carbon atoms. Fraction 3: boiling point range $120\text{-}210\,^\circ\text{C}$. Which statement is correct?

Fuels

Which statement concerning alkenes is correct?

Alkenes

The diagram illustrates how ethanol is made and shows some important chemistry of ethanol. Substance X $\xrightarrow{\text{fermentation}}$ ethanol $\xrightarrow{\text{process Y}}$ carbon dioxide + substance Z. Which substances are X, Y and Z?

Alcohols

Which of the following statements about aqueous ethanoic acid are correct?

The characteristic properties of acids and bases

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

Chromatography

Which of these substances is a polymer?

Polymers

Which substances are able to be separated by filtration?

Separation and purification

An atom belonging to element R has 15 protons, 16 neutrons and 15 electrons. What is R?

Atomic structure and the Periodic Table

Which row gives the properties of potassium iodide, $\text{KI}$?

Ions and ionic bonds

Which diagram shows a mixture of compounds?

Elements, compounds and mixtures

Rubidium is in Group I of the Periodic Table, while bromine is in Group VII. When rubidium reacts with bromine, an ionic compound is formed. Which row gives the electron change for rubidium and the correct formula for the rubidium ion?

Ions and ionic bonds

‘The gradual spreading of a substance from a region of higher concentration to a region of lower concentration.’ Which process is being described?

Diffusion

Which statement accounts for graphite being used as a lubricant?

Giant covalent structures

Which compound has a formula that includes the greatest number of Group VII atoms?

Group VII properties

The relative atomic mass of chlorine is $35.5$. In relative atomic mass calculations, the mass of a chlorine atom is compared with the mass of which particle?

Relative masses of atoms and molecules

A universal indicator solution is introduced into a neutral concentrated aqueous sodium chloride solution. This solution contains $\text{H}^+$ (hydrogen), $\text{Na}^+$ (sodium), $\text{Cl}^-$ (chloride) and $\text{OH}^-$ (hydroxide) ions, and it is electrolysed. Hydrogen gas is formed at the cathode, while chlorine gas is produced at the anode. What colour change does the indicator in the solution undergo during electrolysis?

Electrolysis

Which energy level diagram shows an endothermic reaction?

Exothermic and endothermic reactions

Which process involves a physical change?

Physical and chemical changes

Which substance can produce energy without requiring oxygen?

Fuels

Nitrogen, $\text{N}_2$, and hydrogen, $\text{H}_2$, may be changed into ammonia, $\text{NH}_3$, with the help of a catalyst. What is the catalyst used for?

Rate of reaction

A reaction is conducted at four different temperatures. At each temperature, the time for the reaction to finish is measured. The results are shown. How does temperature affect the rate of reaction?

Rate of reaction

In the industrial production of sulfuric acid, sulfur dioxide changes into sulfur trioxide. $\text{2SO}_2 + \text{O}_2 \rightarrow \text{2SO}_3$ What kind of reaction is this?

Redox

Oxygen melts at $-219\,^{\circ}\text{C}$ and boils at $-183\,^{\circ}\text{C}$. At what temperature is oxygen in the liquid state?

Solids, liquids and gases

On heating pink crystals of cobalt(II) chloride, water vapour is released and the solid turns blue. $\text{CoCl}_2\!\cdot\!6\text{H}_2\text{O} \rightleftharpoons \text{CoCl}_2 + 6\text{H}_2\text{O}$ What occurs when water is added to the blue solid?

Reversible reactions and equilibrium

Which statement describes a base?

The characteristic properties of acids and bases

Which compound is classified as an acidic oxide?

Oxides

Which statement explains how a flame test is carried out?

Identification of ions and gases

A student carries out an experiment to make pure magnesium sulfate crystals. The diagram illustrates the first step in the preparation. He keeps adding magnesium carbonate until it no longer reacts. Which process should he use for the next step?

Preparation of salts

Which row about elements in the Periodic Table is right?

Arrangement of elements

Tennessine, Ts, is an element that has only recently been discovered. The atomic number of tennessine is 117 and it is positioned directly below astatine in Group VII of the Periodic Table. The patterns in the properties of Group VII elements are shown. Which statement about the properties of tennessine is most likely to be correct?

Group VII properties

A flammable gas has to be taken out of a tank at an industrial plant. For safety, an inert gas is used. Which gas is appropriate?

Noble gases

A substance, X, shows the following characteristics. 1. It has a high melting point. 2. It conducts electricity in both the solid state and the liquid state. 3. It is malleable. 4. It has a high density. What could X be?

Properties of metals

Which diagram most accurately shows the structure of a substance that conducts electricity well at $25\,^{\circ}\text{C}$?

Properties of metals

Which diagram depicts a burette?

Acid–base titrations

Some characteristics of element Y are shown below. • It reacts with hydrochloric acid to produce hydrogen gas. • It reacts with steam, but it does not react with cold water. • The oxide of Y cannot be reduced using carbon. Which element is Y?

Reactivity series

Car exhausts release oxides of nitrogen. Which row best explains why oxides of nitrogen are unwanted in the atmosphere?

Air quality and climate

Water is cleaned by passing it through a series of stages. Four stages are shown below. 1. Chlorine is introduced into the water to destroy any bacteria. 2. The water is run through coarse gravel so that large bits of dirt are removed. 3. The water is run through wire screens so that large twigs are removed. 4. The water is run through fine sand so that small particles are removed. What is the correct sequence for carrying out these stages?

Water

If solid S is heated strongly, gas G is produced. G causes limewater to become cloudy. Name S and G and state the type of reaction that S undergoes.

Physical and chemical changes

The element sulfur occurs in several different minerals. Which mineral has the highest percentage by mass of sulfur?

Relative masses of atoms and molecules

Which structure shows a molecule of ethanol?

Alcohols

Petroleum is split into fractions using fractional distillation. The separation takes place in a fractionating column. The properties of three of these fractions are given below. Which statement is correct?

Fuels

Which statement gives a description of methane?

Alkanes

The flow diagram illustrates the preparation of ethanol and several important reactions of ethanol. substance X $\xrightarrow{\text{fermentation}}$ ethanol $\xrightarrow{\text{process Y}}$ carbon dioxide + substance Z Identify X, Y and Z.

Alcohols

The molecular structure of propane is displayed. Which statement correctly describes the atoms and bonding in propane?

Simple molecules and covalent bonds

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

Chromatography

The diagram shows the structure of compound X. X is part of the same homologous series as ethanoic acid. Which row gives some of the properties of an aqueous solution of X?

Carboxylic acids

Different separation methods depend on substances having different properties. Which property is used by distillation?

Separation and purification

Which of the following statements concerning atomic structure is correct?

Atomic structure and the Periodic Table

Which element is not a metal?

Arrangement of elements

The displayed structure of propane, $\text{C}_3\text{H}_8$, is shown. How many electrons take part in bonding in propane?

Simple molecules and covalent bonds

Rubidium is placed in Group I of the Periodic Table, whereas bromine is in Group VII. When rubidium reacts with bromine, an ionic compound is formed. Which row indicates the electron transfer for rubidium and gives the correct formula of the rubidium ion?

Ions and ionic bonds

‘The gradual movement of a substance from a region of high concentration to a region of low concentration.’ Which process is being described?

Diffusion

Which statement accounts for the use of graphite as a lubricant?

Giant covalent structures

The relative atomic mass of chlorine is $35.5$. In a relative atomic mass calculation, the mass of a chlorine atom is compared with the mass of which particle?

Relative masses of atoms and molecules

An inert electrode pair is used to electrolyse molten sodium chloride. Which row gives the substances produced at the cathode and the anode?

Electrolysis

Ethanol can be used as a fuel. $\text{ethanol} + \text{oxygen} \rightarrow \text{carbon dioxide} + \text{water}$ Which of these statements are correct?

Fuels

Hydrogen and the isotope uranium-235 are both used to produce electricity. What term is used to describe the change that happens to both substances in this context?

Hydrogen–oxygen fuel cells

Which substance can produce energy without needing oxygen?

Fuels

When calcium carbonate reacts with dilute hydrochloric acid, carbon dioxide gas is released. As a result, the reaction mixture loses mass. Four different experiments are carried out. For each reaction mixture, the initial mass and the mass after five minutes are measured. In which experiment is carbon dioxide produced at the highest rate?

Rate of reaction

Silver oxide reacts with magnesium to form silver and magnesium oxide. $\text{Ag}_2\text{O} + \text{Mg} \rightarrow 2\text{Ag} + \text{MgO}$ Which substance is oxidised in this reaction?

Redox

If pink crystals of cobalt(II) chloride are heated, water vapour is released and the solid turns blue. $\text{CoCl}_2\cdot6\text{H}_2\text{O} \rightleftharpoons \text{CoCl}_2 + 6\text{H}_2\text{O}$ What occurs when water is added to the blue solid?

Reversible reactions and equilibrium

What oxide is employed to neutralise acidic gases in a power station?

Oxides

When a dark grey solid element is heated, it turns straight into a purple gas. Which term names this change?

Solids, liquids and gases

In the Periodic Table, Period 3 includes the elements sodium through argon. Element Q is a non-metal in this period. Which of the following statements about Q is correct?

Arrangement of elements

Identical masses of a solid, X, are added one after another to an aqueous solution, Y. After each addition, the pH of the solution is measured until the pH reaches $7$. The results are plotted as shown. What are X and Y?

The characteristic properties of acids and bases

When an aqueous cation reacts with aqueous sodium hydroxide, a white precipitate is formed. The precipitate remains insoluble even after excess sodium hydroxide is added. What is the aqueous cation?

Identification of ions and gases

Vinegar has a pH value of $3$. Which of the following statements about vinegar is correct?

The characteristic properties of acids and bases

A student is doing an experiment to make pure magnesium sulfate crystals. The diagram illustrates the first step in the preparation. He keeps adding magnesium carbonate until there is no further reaction. Which process should he use in the next stage?

Preparation of salts

Which of the following statements about the halogens and their compounds is correct?

Group VII properties

Which compound includes a transition metal ion together with a halide ion?

Transition elements

At an industrial plant, a flammable gas must be taken out of a tank. For safety, an inert gas is used. Which gas is appropriate?

Noble gases

A substance, X, shows these properties: 1 It has a high melting point. 2 It conducts electricity when solid and when molten. 3 It is malleable. 4 It has a high density. What is X?

Properties of metals

A metal M lies between sodium and magnesium in the reactivity series. Which reactions take place with M and its oxide?

Reactivity series

Nickel(II) sulfate is a green solid and it dissolves in water. Which method would be used to separate a pure sample of nickel(II) sulfate crystals from a mixture containing nickel(II) sulfate and sand?

Separation and purification

Mild steel and stainless steel are two alloys that contain the element iron. Which row shows a use for each alloy?

Alloys and their properties

Coke (carbon) and limestone are two raw materials used to extract iron from hematite. When each substance is heated in this process, what type of reaction takes place?

Extraction of metals

Oxides of nitrogen are released from car exhausts. Which row most clearly shows why oxides of nitrogen are undesirable in the atmosphere?

Air quality and climate

Reactions P and Q each generate carbon dioxide. $\text{C}_6\text{H}_{12}\text{O}_6 \xrightarrow{P} \text{CO}_2$ (glucose) $\text{Na}_2\text{CO}_3 \xrightarrow{Q} \text{CO}_2$ (sodium carbonate) Identify the reaction type for P and for Q.

The characteristic properties of acids and bases

Which gas is employed as a food preservative?

Elements, compounds and mixtures

Which calcium compound fails to neutralise an acid soil?

The characteristic properties of acids and bases

Petroleum is divided into fractions by fractional distillation. The separation takes place in a fractionating column. The properties of three of these fractions are listed below. A table shows: - fraction 1: the molecules contain 5-10 carbon atoms - fraction 2: boiling point range $320$-$350\,^{\circ}\text{C}$, the molecules contain 16-24 carbon atoms - fraction 3: boiling point range $120$-$210\,^{\circ}\text{C}$ Which statement below is correct?

Fuels

How many atoms are present in a single molecule of ethanoic acid?

Formulae

The flow diagram illustrates how ethanol is prepared and some key chemistry of ethanol. substance X $\xrightarrow{\text{fermentation}}$ ethanol $\xrightarrow{\text{process Y}}$ carbon dioxide $+$ substance Z Which substances are X, Y and Z?

Alcohols

Which substance is not one of the fractions produced by the fractional distillation of petroleum?

Fuels

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

Chromatography

Some plastics are non-biodegradable. What does the term non-biodegradable mean?

Polymers

What does the term nucleon number mean?

Atomic structure and the Periodic Table

The diagram shows the arrangement of particles in a solid. What might the solid be?

Ions and ionic bonds

In the reaction between magnesium and sulfuric acid, what are the formulae of the products?

The characteristic properties of acids and bases

Which diagram shows how the outer-shell electrons are arranged in a water molecule?

Simple molecules and covalent bonds

Rubidium is in Group I of the Periodic Table, while bromine is in Group VII. When rubidium reacts with bromine to produce an ionic compound, which row gives the electron change for rubidium and the correct formula of the rubidium ion?

Ions and ionic bonds