0620 Chemistry June 2025 Question Paper 22

An ice cube melts. ice cube pool of water What happens to the molecules of water in the ice cube?

A sample of a liquid, X, is heated to a temperature above its boiling point. X is then cooled, so that it condenses and then freezes. Which graph describes the change in temperature of X over time? temperature / °C time / s

Which row gives the number of protons, electrons and neutrons in an atom of zinc? protons electrons neutrons

Which particles have the electronic configuration 2,8,8? an argon atom, Ar an aluminium ion, Al 3+ a sodium ion, Na+ a chloride ion, Cl –

A sample of element Q has two isotopes. Their relative masses and abundances are shown. relative mass of isotope abundance / % 238 244 What is the relative atomic mass of this sample of Q to three significant figures?

Which statement about silicon(IV) oxide, SiO2, is correct?

When 65 g of zinc reacts with 32 g of sulfur, 97 g of zinc sulfide is produced. When 65 g of zinc reacts with 40 g of sulfur, the mass of zinc sulfide produced is still 97 g. Which statement explains this observation?

Aluminium reacts with iron(III) oxide to form aluminium oxide and iron. Which chemical equation for the reaction between aluminium and iron(III) oxide is correct?

The concentration of a solution of aqueous sodium hydroxide is 0.50 mol / dm3. Which mass of sodium hydroxide is used to make 500 cm3 of this solution?

g

Dilute aqueous sodium chloride is electrolysed using platinum electrodes. What is the half-equation for the reaction at the cathode?

Hydrogen–oxygen fuel cells can be used to power vehicles. Which statement about hydrogen–oxygen fuel cells is correct?

A reaction pathway diagram is shown. reactants products energy progress of reaction Which row identifies the type of reaction and how the temperature of the surroundings changes during the reaction? type of reaction temperature of the surroundings

The average bond energy for the C–H bond is 413 kJ / mol. What is the enthalpy change when 1.0 mol of methane molecules is formed from carbon and hydrogen atoms?

Which statement describes the effect of adding a catalyst to a chemical reaction?

Which row describes the conditions used in the manufacture of sulfuric acid by the Contact process? catalyst pressure temperature

Which equations show the underlined species acting as a reducing agent? Fe2O3 + 3CO  2Fe + 3CO2 Fe + CuSO4  FeSO4 + Cu 5Fe2+ + MnO4 – + 8H+  5Fe3+ + Mn2+ + 4H2O Fe(OH)2 + H2SO4  FeSO4 + 2H2O

A farmer incorrectly adds two substances to the soil at the same time. They react together to form a gas which turns damp red litmus paper blue. What are the two substances?

Which row shows the equations for the dissociation of hydrochloric acid and of ethanoic acid in aqueous solution? HCl (aq)
H+(aq) + Cl –(aq) hydrochloric acid HCl (aq) H+(aq) + Cl –(aq) HCl (aq)
H+(aq) + Cl –(aq)

Which three oxides are all acidic?

The table shows some properties of noble gases. noble gas density in g / dm3 boiling point in °C helium 0.2 –269 neon 0.9 –246 argon 1.8 –186 krypton xenon 5.9 –108 Which row predicts the density and the boiling point of krypton? density in g / dm3 boiling point in C

Sodium is a Group I metal. What is a physical property of sodium?

Tennessine (atomic number 117) is a manufactured element that is below astatine in Group VII of the Periodic Table. What is the expected state of tennessine at room temperature and pressure?

When chlorine is bubbled into aqueous sodium bromide, a displacement reaction occurs. Which description of this reaction is correct?

Brass is an alloy of copper. Which statement about brass or copper is correct?

The ionic equations for some reactions between metals and aqueous metal ions are shown. Cu + 2Ag+  2Ag + Cu2+ Mg + Zn2+  Mg2+ + Zn Zn + Cu2+  Cu + Zn2+ Sn + Cu2+  Sn2+ + Cu Which further information can be used to place copper, magnesium, silver, tin and zinc in order of their reactivity?

Zinc is used to galvanise iron to prevent it from rusting. Which statements are correct? Galvanising is an example of a barrier method. If the zinc is scratched, the iron will rust very quickly. Galvanising is an example of sacrificial protection. Zinc is more reactive than iron and so accepts electrons more readily.

Which equation represents a reaction that occurs in a blast furnace during the extraction of iron from hematite?

Water is added separately to anhydrous copper(II) sulfate and to anhydrous cobalt(II) chloride. Which row shows the colour changes? anhydrous copper(II) sulfate anhydrous cobalt(II) chloride

Gases which cause acid rain form in car engines. These gases can be removed using a catalytic converter. Which equation represents the removal of one of these gases using a catalytic converter?

Which statements about carbon dioxide are correct? Carbon dioxide absorbs thermal energy from the Earth. Carbon dioxide increases the thermal energy loss to space. The level of carbon dioxide in the atmosphere has increased due to the burning of fossil fuels. Carbon dioxide is the only gas that causes global warming.

What is the structural formula of butan-2-ol?

Methanol reacts with ethanoic acid to form an ester. What is the displayed formula for this ester? H

Petroleum can be separated into useful fractions by fractional distillation. Which row shows a correct use of the named fraction? fraction use

Ethane reacts with chlorine in the presence of ultraviolet light. Which products are formed?

Ethanol can be made by the fermentation of aqueous glucose and by the catalytic addition of steam to ethene. What are two advantages of making ethanol by the catalytic addition of steam to ethene rather than by the fermentation of aqueous glucose?

The structure of a polymer repeat unit is shown. N H

Which item of apparatus is used to measure exactly 26.3 cm3 of a liquid?

A mixture containing an aqueous salt and an insoluble salt is filtered. X Y Which row describes X and Y? X Y

Pure ethanol has a melting point of –114 °C and a boiling point of 78 °C. What are the melting and boiling points of a sample of ethanol with glucose dissolved in it? melting point / °C boiling point / °C