IGCSE Chemistry 0620 Paper 12, Oct/Nov 2023

The melting points and boiling points of four elements are shown.

In which elements do the particles vibrate about fixed positions at 0 °C? A W and X B W and Z C X and Y D Y and Z

Which statements about clean, dry air are correct? 1 It is a mixture of elements only. 2 It is a mixture of elements and compounds. 3 It contains only non-metals. A 1 and 3 B 1 only C 2 and 3 D 2 only

A representation of an atom is shown. What is the nucleon number of this atom? A 6 B 7 C 12 D 13

Which statement describes isotopes of the same element? A They have different electron arrangements. B They have different nuclear charges. C They have nuclei with masses that are the same. D They have the same number of protons.

Potassium reacts with iodine to form potassium iodide. Which statement about potassium iodide is correct? A Each potassium atom shares a pair of electrons with an iodine atom. B In potassium iodide, the particles of potassium have more protons than electrons. C Potassium iodide has a high melting point because it is a covalent compound. D Potassium iodide has a low melting point because it is an ionic compound.

Which row describes the properties of a simple molecular substance?

Different forms of an element G are used as lubricants and in cutting tools. What is the structure of G? A giant covalent B ionic C metallic D simple covalent

The diagram shows the structure of a molecule of ethyl ethanoate. What is the molecular formula of a molecule of ethyl ethanoate? A $\mathrm{C}\mathrm{H}\mathrm{O}$ B ${\mathrm{C}}_4{\mathrm{H}}_8{\mathrm{O}}_2$ C ${\mathrm{C}}_4({\mathrm{H}}_2{)}_2({\mathrm{O}}_2)$ D ${\mathrm{C}}_2{\mathrm{H}}_4\mathrm{O}$

The formula of a compound containing element X is ${\mathrm{N}\mathrm{a}}_2{\mathrm{X}}_2{\mathrm{O}}_3$. The relative formula mass of the compound is 158. What is the relative atomic mass of X? A 32 B 59.5 C 64 D 119

Limestone is used to reduce sulfur dioxide emissions from coal-fired power stations. The equation for the reaction is shown. $${\mathrm{C}\mathrm{a}\mathrm{C}\mathrm{O}}_3+{\mathrm{S}\mathrm{O}}_2\to {\mathrm{C}\mathrm{a}\mathrm{S}\mathrm{O}}_3+{\mathrm{C}\mathrm{O}}_2$$ What is the smallest mass of ${\mathrm{C}\mathrm{a}\mathrm{C}\mathrm{O}}_3$ required to remove 1 tonne of ${\mathrm{S}\mathrm{O}}_2$? A 1 tonne B 2 tonnes C 64 tonnes D 100 tonnes

Which statement about electrolysis is correct? A Bromine and hydrogen are formed during the electrolysis of molten lead(II) bromide. B Metals are formed at the positive electrode. C Molten covalent compounds are broken down by electricity. D Platinum is used as an inert electrode.

Which statements about hydrogen-oxygen fuel cells are correct? 1 The reaction between hydrogen and oxygen is endothermic. 2 The waste product in a hydrogen-oxygen fuel cell is water. 3 A chemical reaction in the cell produces hydrogen which is used as the fuel. 4 A hydrogen-oxygen fuel cell is used to generate electricity. A 1 and 2 B 1 and 3 C 2 and 4 D 3 and 4

The initial and final temperatures of four different reactions are measured. Which reaction is the least exothermic?

Solid calcium carbonate reacts with dilute hydrochloric acid. Which changes to the reaction conditions increase the rate of reaction?

Zinc reacts slowly with dilute sulfuric acid at room temperature. Bubbles of a gas, L, form on the surface of the zinc. When a small amount of copper is added, the reaction is faster. Which row identifies L and explains why the reaction is faster?

Which reaction shows a colour change from white to blue? A adding water to anhydrous copper(II) sulfate B adding water to hydrated copper(II) sulfate C heating anhydrous copper(II) sulfate D heating hydrated copper(II) sulfate

In a blast furnace, iron(III) oxide is converted to iron and carbon monoxide is converted to carbon dioxide. $${\mathrm{F}\mathrm{e}}_2{\mathrm{O}}_3+3\mathrm{C}\mathrm{O}\to 2\mathrm{F}\mathrm{e}+3{\mathrm{C}\mathrm{O}}_2$$ What happens to each of these reactants? A Both iron(III) oxide and carbon monoxide are oxidised. B Both iron(III) oxide and carbon monoxide are reduced. C Iron(III) oxide is oxidised and carbon monoxide is reduced. D Iron(III) oxide is reduced and carbon monoxide is oxidised.

Which products are formed when magnesium carbonate reacts with dilute hydrochloric acid? A carbon dioxide, hydrogen and magnesium chloride B carbon dioxide and magnesium chloride only C carbon dioxide, water and magnesium chloride D water and magnesium chloride only

Which element forms an oxide that reacts with an aqueous solution of a base? A argon B sulfur C magnesium D copper

Which salt is insoluble? A barium sulfate B lead(II) nitrate C magnesium chloride D sodium carbonate

Some properties of element R are shown.

In which part of the Periodic Table is R found? A Group I B Group VII C Group VIII D transition elements

Lithium, sodium and potassium are elements in Group I. Statements about these elements are listed. 1 Lithium is more dense than sodium. 2 Sodium is more reactive than potassium. 3 They all conduct electricity at room temperature. 4 They all react with oxygen at room temperature. Which statements are correct? A 1 and 2 B 1 and 4 C 2 and 3 D 3 and 4

An outline of the Periodic Table is shown. Which name is given to the elements in column Y? A alkali metals B halogens C noble gases D transition elements

Which row describes the properties of a metal that can be used in the manufacture of aircraft?

Which metallic element is added to iron in the manufacture of stainless steel? A carbon B copper C lead D nickel

Which statement about the uses of metals is correct? A Aluminium is used in the manufacture of overhead electrical cables as it has a high density. B Aluminium is used to make food containers as it conducts electricity. C Stainless steel is used in cutlery because it is resistant to rusting. D Stainless steel is used to make chemical reactors because it is a soft alloy.

The list gives the order of some metals and hydrogen in the reactivity series. Metal X is also included.

Which row shows the properties of metal X?

Which gas in the air is needed for iron to rust? A argon B carbon dioxide C nitrogen D oxygen

Why is limestone added to the blast furnace? A It neutralises the molten slag produced. B It reacts with impurities to form slag. C It releases carbon dioxide which reduces the iron(III) oxide. D It removes acidic gases such as carbon dioxide.

Which process removes carbon dioxide from the atmosphere? A photosynthesis B thermal decomposition of calcium carbonate C combustion of fossil fuels D reaction of sodium carbonate with an acid

The flow chart shows stages in the treatment of river water to produce drinking water. $$\text{river water}\to \text{sedimentation tank}\to \text{stage J}\to \text{stage K}\to \text{drinking water}$$ What occurs at stages J and K?

Which two compounds can be mixed together to form an NPK fertiliser? A ammonium phosphate and calcium hydroxide B calcium phosphate and ammonium nitrate C potassium nitrate and calcium oxide D potassium phosphate and ammonium nitrate

What are the main substances produced by the fractional distillation of liquid air? A oxygen and carbon dioxide B oxygen and nitrogen C helium and nitrogen D hydrogen and oxygen

Which diagram shows the displayed formula for the named organic compound? A ethanoic acid B ethene C ethanol D methane

Poly(ethene) is formed from petroleum using three separate processes. In which order are the processes used? A cracking $\to$ fractional distillation $\to$ polymerisation B cracking $\to$ polymerisation $\to$ fractional distillation C fractional distillation $\to$ cracking $\to$ polymerisation D fractional distillation $\to$ polymerisation $\to$ cracking

Gas oil and naphtha are two fractions obtained from petroleum. What are uses of gas oil and naphtha?

Ethene can be polymerised. Which diagram represents the structure of the product formed?

An acid–base titration is described. ● $25.0{\text{ cm}}^3$ of dilute aqueous alkali is put into a conical flask. ● Indicator is added to the flask. ● Dilute acid is added to the aqueous alkali until the indicator changes colour. ● The volume of acid used is then recorded. Which use of apparatus is correct? A The $25.0{\text{ cm}}^3$ of aqueous alkali is measured using a volumetric pipette. B The $25.0{\text{ cm}}^3$ of aqueous alkali is measured using the lines on the conical flask. C The volume of acid is measured using a measuring cylinder. D The volume of acid is measured using a volumetric pipette.

The apparatus shown is used to separate a mixture. What is the mixture? A anhydrous copper(II) sulfate and hydrated copper(II) sulfate B sodium chloride and sand C ethanol and methanol D iron and steel

The results of tests on three gases, X, Y and Z, are shown.

What are X, Y and Z?