Feb/March 2019

The four processes below are given. 1 Brownian motion 2 condensation 3 diffusion 4 evaporation Which of these processes involve a change of state?

Solids, liquids and gases

As shown, two electrolysis experiments were performed. The graphite electrodes are numbered 1-4. In one experiment, molten sodium chloride is used, while in the other, concentrated aqueous sodium chloride is used. Which row gives the products formed at the electrodes in these experiments?

Electrolysis

A sample of 10 g of ammonium nitrate is put into water at $25\degree\text{C}$, and the mixture is stirred. The ammonium nitrate dissolves, and after one minute the temperature of the solution becomes $10\degree\text{C}$. Which word describes this change?

Exothermic and endothermic reactions

Which process is associated with a chemical change?

Physical and chemical changes

Chunks of limestone react with dilute hydrochloric acid as represented by the equation below. $\text{CaCO}_3 + 2\text{HCl} \rightarrow \text{CaCl}_2 + \text{H}_2\text{O} + \text{CO}_2$. Which alteration in the conditions would decrease the rate of reaction?

Rate of reaction

Which reaction can be reversed?

Reversible reactions and equilibrium

The equation shows the reaction of magnesium with carbon dioxide. $2\text{Mg} + \text{CO}_2 \rightarrow 2\text{MgO} + \text{C}$. Which statement correctly describes the change taking place in this reaction?

Redox

Barium hydroxide is an alkali. It reacts with hydrochloric acid. How does the pH of the hydrochloric acid change as excess aqueous barium hydroxide is added?

The characteristic properties of acids and bases

Copper(II) sulfate crystals have a blue colour. They are prepared by first adding copper(II) oxide in excess to sulfuric acid. The mixture is then heated and stirred. After this, it is filtered and the filtrate is left to evaporate, producing blue crystals. Why is filtration necessary?

Separation and purification

The outcomes of two tests carried out on an aqueous solution of X are given below. Test: aqueous sodium hydroxide added – a green precipitate formed. Test: acidified aqueous silver nitrate added – a yellow precipitate formed. What is X?

Identification of ions and gases

Data on the solubility of four oxides in water is given. Which oxide, after being added to water, produces a solution with a pH less than $7$?

Oxides

A student records how long $2.0\,\text{g}$ of magnesium takes to dissolve in $50\,\text{cm}^3$ of dilute sulfuric acid. Which piece of apparatus is needed for this experiment?

Rate of reaction

The elements sodium through argon make up Period 3 of the Periodic Table. Which row best shows the pattern across Period 3 from left to right?

Arrangement of elements

Astatine is placed beneath iodine in Group VII of the Periodic Table. Which row shows the properties of astatine?

Group VII properties

Which row gives the description of a transition element?

Transition elements

Which statement accounts for the fact that elements in Group VIII of the Periodic Table are unreactive?

Noble gases

Magnesium’s electrical conductivity was investigated. Magnesium was then placed into dilute sulfuric acid, and a gas, Q, was formed. Which row is correct?

Properties of metals

Four reactions occurring in the blast furnace to make iron are shown. Which reaction is used to maintain the temperature of the furnace?

Extraction of metals

The table shows the position of some metals and hydrogen in the reactivity series. Metal X is included too. highest reactivity: K, Mg, Zn, H, X, Cu: lowest reactivity Which row gives the correct properties of metal X?

Reactivity series

The properties of four elements are given below. Which element is used for making aircraft bodies?

Uses of metals

The diagram illustrates how water is processed so that it becomes safe to drink. stage 1: reservoir of water $\rightarrow$ stage 2 $\rightarrow$ stage 3: chlorination $\rightarrow$ stage 4: drinking water What takes place in stage 2?

Water

A farmer applies calcium hydroxide to a field in order to reduce its acidity. If the farmer then puts ammonium nitrate fertiliser onto the same field straight after the calcium hydroxide, the two substances react. Why does this reaction reduce the effectiveness of the fertiliser?

Fertilisers

What method is used to separate a mixture of two liquids?

Separation and purification

Which row that shows an air pollutant and its main source is incorrect?

Air quality and climate

What substances are necessary for iron to rust?

Corrosion of metals

Methane and carbon dioxide are both greenhouse gases. Which row shows one source of methane and one source of carbon dioxide?

Air quality and climate

Which element has an oxide that is used as a food preservative?

Oxides

Lime is produced by heating limestone. Which equation shows this reaction?

Formulae

A large number of items made from synthetic polymers remain usable for many years. Why do these polymers remain unchanged for such a long time?

Polymers

The structure of a compound, G, is shown. G belongs to the same homologous series as ethanoic acid. Which row gives some of the properties of an aqueous solution of G?

The characteristic properties of acids and bases

The fractional distillation of petroleum is illustrated. Which fraction is the least volatile?

Separation and purification

Which row indicates the properties of methane?

Simple molecules and covalent bonds

The formulae for five compounds are given below: 1. $\text{C}_4\text{H}_{10}$ 2. $\text{C}_2\text{H}_5\text{OH}$ 3. $\text{C}_4\text{H}_9\text{OH}$ 4. $\text{C}_4\text{H}_9\text{COOH}$ 5. $\text{C}_5\text{H}_{11}\text{OH}$ Which of these compounds belong to the same homologous series?

Formulae, functional groups and terminology

Lead(II) iodide does not dissolve in water. Lead(II) iodide is prepared by mixing aqueous lead(II) nitrate with aqueous potassium iodide. Which pieces of apparatus are required to isolate solid lead(II) iodide from $20\,\text{cm}^3$ of aqueous lead(II) nitrate?

Separation and purification

What process is used to produce an alkene from a long-chain alkane?

Alkenes

Which line identifies isotopes belonging to the same element?

Isotopes

Which row gives the structure of the positive ion in sodium chloride?

Ions and ionic bonds

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

Giant covalent structures

What does the term nucleon number of an atom mean?

Atomic structure and the Periodic Table

The relative formula mass, $M_r$, of calcium carbonate, $\text{CaCO}_3$, is $100$. How much carbon is contained in $100\,\text{g}$ of calcium carbonate?

Relative masses of atoms and molecules

At 100 ^{\circ}C, pure water boils. What happens to the water particles as the water boils?

Solids, liquids and gases

Which substance is not formed during the electrolysis of concentrated aqueous sodium chloride?

Electrolysis

In the electrolysis of aqueous copper(II) sulfate with copper electrodes, what ionic half-equations represent the reactions occurring at each electrode?

Electrolysis

10 g of ammonium nitrate is put into water at $25^{\circ}\text{C}$ and the mixture is stirred. The ammonium nitrate dissolves and, after one minute, the solution temperature is $10^{\circ}\text{C}$. Which word describes this change?

Exothermic and endothermic reactions

Hydrogen undergoes reaction with chlorine as shown by the equation: $\text{H}_2(\text{g}) + \text{Cl}_2(\text{g}) \rightarrow 2\text{HCl}(\text{g})$. This reaction gives out heat. Which statement about this reaction is correct?

Exothermic and endothermic reactions

Hydrogen-oxygen fuel cells may be used to drive cars. Platinum acts as a catalyst. The energy produced per gram for three fuels is shown. Which statement is correct and is an advantage of a hydrogen-oxygen fuel cell?

Hydrogen–oxygen fuel cells

A student puts dilute hydrochloric acid at two different temperatures onto two separate lumps of limestone. The limestone lumps each have the same mass. The carbon dioxide gas formed is gathered in a gas syringe. The volume of carbon dioxide collected in 1 minute at each temperature is shown. Which row gives the description and explanation of the results at $50^{\circ}\text{C}$ compared with $25^{\circ}\text{C}$?

Rate of reaction

Which reaction can be reversed?

Reversible reactions and equilibrium

A gas syringe was charged with some nitrogen dioxide gas. The syringe tip is then sealed. A reversible reaction takes place and eventually equilibrium is established: $2\text{NO}_2(\text{g}) \rightleftharpoons \text{N}_2\text{O}_4(\text{g})$. The forward reaction is exothermic. Which statement about this reaction is correct?

Reversible reactions and equilibrium

The chemical reaction between magnesium and carbon dioxide is represented by the equation: $2\text{Mg} + \text{CO}_2 \rightarrow 2\text{MgO} + \text{C}$. Which statement correctly explains what occurs in this reaction?

Redox

Which of these changes show reduction?

Redox

What separation method should be used to separate a mixture of two liquids?

Separation and purification

Barium hydroxide is an alkali that reacts with hydrochloric acid. What happens to the pH of the hydrochloric acid as excess aqueous barium hydroxide is added?

Acid–base titrations

Which statement gives a chemical property of aluminium oxide, $\text{Al}_2\text{O}_3$?

Oxides

The outcomes of two tests carried out on an aqueous solution of X are shown. What is X?

Identification of ions and gases

The four stages for preparing an insoluble salt are shown below. 1 drying 2 filtration 3 precipitation 4 washing What is the correct sequence for carrying out these stages?

Preparation of salts

The elements sodium through to argon make up Period 3 in the Periodic Table. Which row shows the pattern across Period 3 from left to right?

Arrangement of elements

Astatine is located below iodine in Group VII of the Periodic Table. Which row gives the properties of astatine?

Group VII properties

Which statement gives the reason that elements in Group VIII of the Periodic Table do not react easily?

Noble gases

In which reaction are Fe(s) ions formed when the mixture is heated?

Redox

The list shows the arrangement of some metals and hydrogen in the reactivity series. Metal X is included as well. most reactive: K, Mg, Zn, H, X, Cu: least reactive Which row correctly displays the properties of metal X?

Reactivity series

When heated, which metal carbonate does not give off carbon dioxide?

Group I properties

Lead(II) iodide does not dissolve in water. It is produced by adding aqueous lead(II) nitrate to aqueous potassium iodide. Which apparatus is required to separate and collect solid lead(II) iodide from $20\,\text{cm}^3$ of aqueous lead(II) nitrate?

Separation and purification

Which of the following statements about the extraction of metals is correct?

Extraction of metals

The diagram illustrates how water is treated so that it is fit for drinking. stage 1: water reservoir → stage 2 → stage 3: chlorination → stage 4: drinking water What takes place in stage 2?

Water

Which are the principal substances obtained from the fractional distillation of liquid air?

Separation and purification

The raw materials used in the Haber process are hydrogen and nitrogen. From what sources are the hydrogen and nitrogen obtained?

Fertilisers

Which process takes carbon dioxide out of the Earth’s atmosphere?

Air quality and climate

The Contact process is used to produce sulfuric acid. The stages in the process are shown below. 1 Dissolve sulfur trioxide in 98% concentrated sulfuric acid. 2 Heat sulfur strongly in air. 3 Add oleum to water. 4 Pass sulfur dioxide over a vanadium(V) oxide catalyst. Which order of steps is correct?

Preparation of salts

A diagram of the fractional distillation of petroleum is shown. Which fraction is the least volatile?

Separation and purification

Which of the following statements about members of a homologous series is correct?

Formulae, functional groups and terminology

Ethanol is produced in large quantities by fermentation. Which statement about fermentation is correct?

Alcohols

The structure of a compound, G, is illustrated. G belongs to the same homologous series as ethanoic acid. Which row gives some of the properties of an aqueous solution of G?

Carboxylic acids

The chromatogram for substance S is displayed. Distances W, X, Y and Z are marked on the diagram. How is the $R_f$ value of substance S determined?

Chromatography

Which statement regarding polymers is correct?

Polymers

Which row gives isotopes of one element?

Isotopes

Which row shows the structure of the positive ion in sodium chloride?

Ions and ionic bonds

Which statement concerning copper, diamond and silicon(IV) oxide is correct?

Giant covalent structures

A nitrogen oxide contains the following percentages by mass: N, 30.4%; O, 69.6%. Its relative molecular mass is 92. Determine the molecular formula of this nitrogen oxide.

Formulae

The equation shown represents calcium carbonate reacting with dilute hydrochloric acid. $\text{CaCO}_3 + 2\text{HCl} \rightarrow \text{CaCl}_2 + \text{CO}_2 + \text{H}_2\text{O}$. $10\,\text{g}$ of calcium carbonate is reacted with $100\,\text{cm}^3$ of $1\,\text{mol dm}^{-3}$ hydrochloric acid. The statements below are given. Which statements about the reaction are correct?

The mole and the Avogadro constant

This question concerns electronic structures. The electronic structures of five atoms, A, B, C, D and E, are shown. Use these electronic structures to answer the following questions. Each electronic structure may be used once, more than once, or not at all.

Atomic structure and the Periodic Table

This question concerns uranium and compounds of uranium.

Isotopes

This question concerns sulfur, sulfur compounds, and water obtained from a sulfur spring. A sulfur spring is a natural water source that contains sulfur.

Identification of ions and gases

A student carried out an investigation into the reaction of zinc with dilute hydrochloric acid by recording the volume of hydrogen gas produced at 1 minute intervals. $\text{Zn} + 2\text{HCl} \rightarrow \text{ZnCl}_2 + \text{H}_2$

Rate of reaction

Aqueous sodium hydroxide acts as a base.

The characteristic properties of acids and bases

This question concerns chromium and chromium compounds.

Electrolysis

This question concerns alkanes and petroleum fractions.

Alkanes

Period 3 from the Periodic Table is displayed below. sodium magnesium aluminium silicon phosphorus sulfur chlorine argon Use only these elements to answer the questions. An element may be chosen once, more than once, or not chosen at all. State which element:

Arrangement of elements

Complete the table below.

Elements, compounds and mixtures

Fluorine belongs to Group VII. Fluorine makes compounds with metals and non-metals.

Group VII properties

The topic of this question is ethanoic acid, $\text{CH}_3\text{COOH}$.

Carboxylic acids

Titanium is extracted from the ore rutile. Rutile is an impure form of titanium(IV) oxide, $\text{TiO}_2$.

Extraction of metals

This question concerns transition elements.

Transition elements