Oct/Nov 2021

Decane has a freezing point of $-30^\circ\text{C}$ and a boiling point of $174^\circ\text{C}$. A small quantity of decane is put into an open beaker inside an oven maintained at $120^\circ\text{C}$ and at atmospheric pressure for 24 hours. What will happen to the decane sample?

Solids, liquids and gases

Which of the following statements about the products formed during electrolysis, using inert electrodes, are correct?

Electrolysis

When aqueous ethanoic acid reacts with solid sodium carbonate to produce a salt, the temperature falls. What kind of reaction and what energy change take place?

The characteristic properties of acids and bases

What gas is used as a fuel?

Fuels

Solid copper(II) carbonate reacts with dilute sulfuric acid. $\text{CuCO}_3 + \text{H}_2\text{SO}_4 \rightarrow \text{CuSO}_4 + \text{CO}_2 + \text{H}_2\text{O}$. The reaction rate may be altered by changing the conditions. Which of the following changes will always increase the rate of this chemical reaction?

Rate of reaction

Several changes are listed in the table. In which rows are the changes described accurately?

Physical and chemical changes

X is a pink solid, while Y is a blue solid. On heating X, water is given off and the solid changes to blue. If water is then added to Y, the solid becomes pink. What are X and Y?

Physical and chemical changes

Carbon combines with carbon dioxide as shown. $\text{CO}_2 + \text{C} \rightarrow 2\text{CO}$. Which statement about this reaction is correct?

Redox

Which substances, when reacted together, do not form water as a product?

The characteristic properties of acids and bases

When magnesium ribbon is exposed to air, its surface forms magnesium oxide. Which statement explains why dilute hydrochloric acid can remove this magnesium oxide layer?

The characteristic properties of acids and bases

Copper(II) chloride crystals are prepared by adding solid copper(II) carbonate to dilute hydrochloric acid until no more dissolves. What process is used to obtain pure copper(II) chloride crystals from the mixture?

Separation and purification

A student transferred exactly $25.00\,\text{cm}^3$ of dilute hydrochloric acid into a conical flask. The student then added $2.5\,\text{g}$ of solid sodium carbonate and recorded how the temperature of the mixture changed. Which apparatus does the student need to use?

Exothermic and endothermic reactions

Which of the following statements about aqueous sodium hydroxide is correct?

The characteristic properties of acids and bases

A section of the Periodic Table is shown. The letters do not represent their chemical symbols. Which statement is correct?

Arrangement of elements

What products are formed when sodium reacts with water?

Group I properties

Element X has a high density, a high melting point and a high electrical conductivity. It also forms many coloured compounds. Both Element X and many of its compounds are used as catalysts. What might be the atomic number of X?

Transition elements

The noble gases are found in Group VIII of the Periodic Table. Which statement accounts for why noble gases are unreactive?

Noble gases

Which statement is true for all metals?

Properties of metals

Which statement concerning the extraction of metals is correct?

Extraction of metals

Which row correctly shows a use of mild steel and a use of stainless steel?

Uses of metals

The diagrams illustrate several ways water is used in the home. For which of these uses is it important that the water has been treated?

Water

Which air pollutants are able to damage buildings built from limestone?

Air quality and climate

A student removes sugar from fragments of broken glass by dissolving the sugar in water and then filtering off the broken glass. What is the filtrate?

Separation and purification

Which of the following statements about fertilisers is correct?

Fertilisers

Sulfur is burned to produce sulfur dioxide. Which row gives a source of sulfur and a use for sulfur dioxide?

Oxides

A factory’s waste water is treated using lime (calcium oxide). Which substance is taken out by the lime?

Water

Which compound has been given the correct name?

Naming organic compounds

When fuel X burns in air, it forms carbon dioxide and water. Fuel Y does the same. What might X and Y be?

Fuels

What hydrocarbon is the principal component of natural gas?

Fuels

Which of the following statements about ethene are correct?

Alkenes

A section of the structure of a very large molecule is shown. Which term is used for the small unit that combines to form this molecule?

Polymers

How many single covalent bonds are present in one molecule of ethanol in total?

Simple molecules and covalent bonds

Which statement is correct for aqueous ethanoic acid?

The characteristic properties of acids and bases

The isotopes $^{12}\text{C}$ and $^{14}\text{C}$ are both forms of carbon. Which statement about these isotopes is correct?

Isotopes

Three statements concerning synthetic polymers are given. Which of these statements are correct?

Polymers

Which statement correctly describes brass?

Alloys and their properties

Livermorium, Lv, was discovered in 2000. Which statement predicts what occurs to an Lv atom when it becomes an $\text{Lv}^{2-}$ ion?

Ions and ionic bonds

Which substance is a covalent compound with two atoms per molecule?

Simple molecules and covalent bonds

Which statement regarding carbon is correct?

Elements, compounds and mixtures

Sodium chlorate(V) is written as $\text{NaClO}_3$. What is the relative formula mass of sodium chlorate(V), $\text{NaClO}_3$?

Relative masses of atoms and molecules

Which row shows what happens to the particles in solid iodine as it is heated and changes into a gas?

Solids, liquids and gases

Iron can be electroplated with zinc so that it becomes resistant to corrosion. Which row concerning the electroplating of iron with zinc is correct?

Electrolysis

The energy level diagram for the reaction of substance X with substance Y to produce substance Z is shown. Which of the following statements is correct?

Exothermic and endothermic reactions

Which of these reactions are exothermic? 1. $\text{C} + \text{O}_2 \rightarrow \text{CO}_2$ 2. $\text{CH}_4 + 2\text{O}_2 \rightarrow \text{CO}_2 + 2\text{H}_2\text{O}$ 3. $2\text{H}_2 + \text{O}_2 \rightarrow 2\text{H}_2\text{O}$

Exothermic and endothermic reactions

Solid copper(II) carbonate is reacted with dilute sulfuric acid. $\text{CuCO}_3 + \text{H}_2\text{SO}_4 \rightarrow \text{CuSO}_4 + \text{CO}_2 + \text{H}_2\text{O}$ Which of these changes will always make this chemical reaction faster? 1. raising the concentration of sulfuric acid 2. making the pieces of copper(II) carbonate larger 3. raising the temperature 4. raising the volume of sulfuric acid

Rate of reaction

When a piece of marble is placed into hydrochloric acid, bubbles of carbon dioxide gas are released. Which method is used to determine the rate of the reaction?

Rate of reaction

Solid X is heated strongly. Its colour changes from blue to white. Which substance is solid X?

Preparation of salts

What change does a chemical substance undergo during reduction?

Redox

Which of the following statements about acids and bases are correct? 1. When an acid reacts with a metal, hydrogen is released. 2. When a base reacts with an ammonium salt, ammonia is given off. 3. When an acid reacts with a carbonate, carbon dioxide is released. 4. With methyl orange, alkaline solutions appear orange.

The characteristic properties of acids and bases

Oxide 1 is a solid and it reacts with dilute hydrochloric acid. Oxide 2 is a gas and it reacts with sodium hydroxide solution. What are the formulae of these oxides?

Oxides

During the preparation of zinc sulfate crystals, an excess of zinc oxide is mixed with dilute sulfuric acid. Why is the zinc oxide used in excess?

Preparation of salts

A student poured exactly $25.00\,\text{cm}^3$ of dilute hydrochloric acid into a conical flask. Then the student added $2.5\,\text{g}$ of solid sodium carbonate and recorded the temperature change of the mixture. Which apparatus does the student need to use?

Exothermic and endothermic reactions

Which statement concerning aqueous sodium hydroxide is correct?

The characteristic properties of acids and bases

A section of the Periodic Table is displayed. The letters are not their chemical symbols. Which statement is correct?

Arrangement of elements

Which of the following statements about the elements in Group VII of the Periodic Table is correct?

Group VII properties

A section of the Periodic Table is shown. Which element is a transition element?

Transition elements

The noble gases are placed in Group VIII of the Periodic Table. Which statement accounts for why noble gases are unreactive?

Noble gases

Which statement applies to all metals?

Properties of metals

Which row shows the extraction methods of aluminium and iron from their ores?

Extraction of metals

Which statement concerning metals and their uses is correct?

Uses of metals

The diagrams illustrate several ways water is used in the home. For which of these uses does the water need to have been treated?

Water

Four separate test tubes, each with water and an iron nail, are left for two weeks. Which nail had the smallest amount of rusting?

Corrosion of metals

A student removes sugar from fragments of broken glass by dissolving the sugar in water, then filtering out the broken glass. What is the filtrate?

Separation and purification

Which process does not release a greenhouse gas?

Air quality and climate

When sulfur is burned, sulfur dioxide is formed. Which row gives a source of sulfur and a use of sulfur dioxide?

Oxides

Lime (calcium oxide) is added to clean waste water from a factory. Which substance does the lime remove?

The characteristic properties of acids and bases

The complete combustion of methane is represented by the chemical equation below. $\text{2CH}_4 + z\text{O}_2 \rightarrow \text{2CO}_2 + \text{4H}_2\text{O}$ What is the value of $z$?

Formulae

Fuel X gives carbon dioxide and water when it is combusted in air. Fuel Y does the same. What might X and Y be?

Fuels

Which substance is not considered to be a fossil fuel?

Fuels

Which compound is in a different homologous series from the rest?

Formulae, functional groups and terminology

What is one property of aqueous ethanoic acid?

The characteristic properties of acids and bases

Which of these statements about unsaturated hydrocarbons are correct?

Alkenes

Which substance is fermented to make alcohol?

Alcohols

In one atom of the isotope $^{{27}}_{{13}}\text{Al}$, how many protons, neutrons and electrons are present?

Isotopes

Which of the following statements are correct?

Elements, compounds and mixtures

Which statement correctly describes brass?

Alloys and their properties

Rubidium belongs to Group I and iodine belongs to Group VII in the Periodic Table. Which row shows what occurs when rubidium reacts with iodine to make rubidium iodide?

Ions and ionic bonds

Which row displays the properties of an ionic compound?

Ions and ionic bonds

Which substance is classified as a macromolecule?

Giant covalent structures

Sodium chlorate(V) can be represented by the formula $\text{NaClO}_3$. What is the relative formula mass of sodium chlorate(V), $\text{NaClO}_3$?

Relative masses of atoms and molecules

The particles in a substance are widely spaced, arranged at random and moving around. The substance then changes state, and the particles become close together. They are still arranged at random and can move. What is the change of state of the substance?

Solids, liquids and gases

Fizzing is seen at the negative electrode (cathode) in the electrolysis of concentrated aqueous sodium chloride. Which element is formed at the negative electrode (cathode)?

Electrolysis

An energy level diagram for a chemical reaction is shown. Which statement about this reaction is correct?

Exothermic and endothermic reactions

Which property accounts for methane being used as a fuel?

Fuels

Solid copper(II) carbonate is reacted with dilute sulfuric acid. $\text{CuCO}_3 + \text{H}_2\text{SO}_4 \rightarrow \text{CuSO}_4 + \text{CO}_2 + \text{H}_2\text{O}$ The rate of the reaction may be altered by changing the conditions. Which changes will always make the rate of this chemical reaction higher?

Rate of reaction

Magnesium carbonate and hydrochloric acid combine to produce a gas. The gas volume is recorded at regular time intervals. In experiment 1, excess magnesium carbonate granules react with $100\,\text{cm}^3$ of hydrochloric acid. The experiment is then carried out again, but with one alteration. This is experiment 2. The findings are displayed on the graph. What change has been made?

Rate of reaction

What colour change is seen when water is added to anhydrous cobalt(II) chloride?

Identification of ions and gases

The equation representing the extraction of iron from its ore is given below. $\text{Fe}_2\text{O}_3 + 3\text{CO} \rightarrow 2\text{Fe} + 3\text{CO}_2$ Which statement is correct?

Extraction of metals

Solution X is checked separately with sodium carbonate and litmus. Which row indicates that X is acidic?

The characteristic properties of acids and bases

Basic oxides are neutralised by acidic oxides. Which element produces an oxide that neutralises calcium oxide?

Oxides

Which method is used to obtain a pure sample of copper(II) sulfate crystals?

Preparation of salts

A student placed exactly $25.00\,\text{cm}^3$ of dilute hydrochloric acid into a conical flask. The student then added $2.5\,\text{g}$ of solid sodium carbonate and recorded the temperature change of the mixture. Which apparatus does the student need to use?

Exothermic and endothermic reactions

Which of the following statements about aqueous sodium hydroxide is correct?

The characteristic properties of acids and bases

A section of the Periodic Table is shown. The letters are not chemical symbols. Which statement is true?

Arrangement of elements

Lithium, sodium and potassium are elements in Group I of the Periodic Table. Which statement concerning sodium is correct?

Group I properties

Which characteristic of transition elements differs from the characteristics of Group I metals?

Transition elements

Noble gases are found in Group VIII of the Periodic Table. Which statement gives the reason why noble gases are unreactive?

Noble gases

Which statement applies to every metal?

Properties of metals

Chromium is more reactive than iron, but it is less reactive than zinc. Which of the following statements are correct?

Reactivity series

Some properties of copper are shown. Which of these properties makes copper suitable for a cooking pan?

Properties of metals

The diagrams illustrate a few ways water is used in the home. For which of these uses is it important that the water has been treated?

Water

When slaked lime, $\text{Ca(OH)}_2$, is added to soil that has already been treated with ammonium sulfate fertiliser, which gas is given off?

The characteristic properties of acids and bases

A student separates sugar from fragments of broken glass by dissolving the sugar in water and then filtering out the broken glass. What does the filtrate refer to?

Separation and purification

Which reactions give carbon dioxide?

Preparation of salts

Sulfur can be burned to form sulfur dioxide. Which row gives a source of sulfur and a use for sulfur dioxide?

Elements, compounds and mixtures

Lime (calcium oxide) is used to treat wastewater from a factory. Which substance is taken out by the lime?

The characteristic properties of acids and bases

The structures of three chemical compounds are shown. Which homologous series do 1, 2 and 3 belong to?

Formulae, functional groups and terminology

When fuel X is burnt in air, it forms carbon dioxide and water. Fuel Y does the same. What might X and Y be?

Fuels

Which substance forms the largest part of natural gas?

Fuels

Which statement is used to describe the members of a homologous series?

Formulae, functional groups and terminology

What monomer molecules are required to make poly(ethene)?

Polymers

Ethanol is made by reacting compound P with steam in the presence of a catalyst. What is P?

Alkenes

What characteristic is displayed by aqueous ethanoic acid?

The characteristic properties of acids and bases

The nucleus of one atom contains nineteen particles. Nine of these are positively charged, while ten have no charge. Which statement about this nucleus is correct?

Atomic structure and the Periodic Table

Which statement regarding polymers is correct?

Polymers

Which statement correctly describes brass?

Alloys and their properties

When a Group I element reacts with a Group VII element, an ionic bond is formed. Which row illustrates the changes in electronic structures?

Ions and ionic bonds

Four covalent compounds are shown below. chlorine methane ammonia water Which row shows the total number of covalent bonds in each compound?

Simple molecules and covalent bonds

When magnesium is added to dilute hydrochloric acid, a salt and hydrogen gas are formed. What is the equation for this reaction?

The characteristic properties of acids and bases

Sodium chlorate(V) has the formula $\text{NaClO}_3$. Calculate the relative formula mass of sodium chlorate(V), $\text{NaClO}_3$.

Relative masses of atoms and molecules