Exothermic and endothermic reactions — Paper 1 · IGCSE Science - Combined 0653

26 Why is water often used to extinguish fires? A Water is a compound. B Water is neutral. C Water reacts with most fuels. D Water removes heat from the fire.

1 marks

Answer: D

This question in 0653/11 Oct/Nov 2006

26 Why is water often used to extinguish fires? A The boiling point of water is 100 °C B Water is a compound containing oxygen and hydrogen. C Water removes heat from the fire. D Water reacts with most fuels.

1 marks

Answer: C

This question in 0653/11 May/June 2008

15 On heating iron and sulphur together, the mixture starts to glow. The glow then continues even when the heating is stopped. In this reaction, ……1…… heat is given out and a new ……2…… is formed. Which words correctly complete gaps 1 and 2? 1 2 A no element B no compound C some element D some compound

1 marks

Answer: D

This question in 0653/11 Oct/Nov 2008

27 Kerosene is a hydrocarbon fuel obtained from crude oil. Which statement is correct? A Kerosene burns to form carbon dioxide and water. B Kerosene contains the elements carbon, hydrogen and oxygen. C Kerosene is used as a fuel for cars. D The combustion of kerosene is an endothermic reaction.

1 marks

Answer: A

This question in 0653/12 May/June 2011

23 Ethene burns as shown. C2H4(g) + 3O2(g) → 2CO2(g) + 2H2O(l) What happens to ethene in this reaction? A decomposition B neutralisation C oxidation D reduction

1 marks

Answer: C

This question in 0653/11 Oct/Nov 2011

16 The reaction of zinc and sulfur to form zinc sulfide is exothermic. Which information in the table is correct? energy change elements in during the formation of zinc sulfide zinc sulfide A difficult to separate heat given out B difficult to separate heat taken in C easy to separate heat given out D easy to separate heat taken in

1 marks

Answer: A

This question in 0653/12 May/June 2013

26 Which statements about the complete combustion of methane are correct? 1 The reaction is endothermic. 2 Carbon dioxide is formed. 3 Water is formed. A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

1 marks

Answer: D

This question in 0653/12 May/June 2013

15 The reaction of zinc and sulfur to form zinc sulfide is exothermic. Which information in the table is correct? energy change elements in during the formation of zinc sulfide zinc sulfide A difficult to separate heat given out B difficult to separate heat taken in C easy to separate heat given out D easy to separate heat taken in

1 marks

Answer: A

This question in 0653/13 May/June 2013

27 The diagram shows how the temperature change can be measured when magnesium reacts with hydrochloric acid. magnesium powder dilute hydrochloric acid Thermometer reading before adding magnesium powder = 20.6 °C Thermometer reading after adding magnesium powder = 32.4 °C Which statement is correct? A The reaction is endothermic and gives out heat. B The reaction is endothermic and takes in heat. C The reaction is exothermic and gives out heat. D The reaction is exothermic and takes in heat.

1 marks

Answer: C

This question in 0653/13 Oct/Nov 2013

21 The table shows the initial and final temperatures in a series of experiments. Which experiment is most exothermic? initial temperature final temperature / °C / °C A 16.0 24.0 B 18.5 27.0 C 17.5 26.5 D 18.5 14.0

1 marks

Answer: C

This question in 0653/11 Oct/Nov 2014

20 The table shows the initial and final temperatures in a series of experiments. Which experiment is most exothermic? initial temperature final temperature / °C / °C A 16.0 24.0 B 18.5 27.0 C 17.5 26.5 D 18.5 14.0

1 marks

Answer: C

This question in 0653/12 Oct/Nov 2014

21 The initial and final temperatures of two chemical reactions are shown. initial temperature final temperature reaction / °C /.°C 1 19 23 2 20 16 Which statement is correct? A Both reactions are endothermic. B Both reactions are exothermic. C Reaction 1 is endothermic and reaction 2 is exothermic. D Reaction 1 is exothermic and reaction 2 is endothermic.

1 marks

Answer: D

This question in 0653/13 Oct/Nov 2014

23 Gasoline is a hydrocarbon fuel obtained from crude oil. Which statement is correct? A Gasoline burns to form carbon dioxide and water. B Gasoline contains the elements carbon, hydrogen and oxygen. C Gasoline is used as a fuel for diesel engines. D The combustion of gasoline is an endothermic reaction.

1 marks

Answer: A

This question in 0653/13 Oct/Nov 2014

18 Sherbet is a mixture of citric acid and sodium hydrogencarbonate. When sherbet is eaten, the chemicals react and cool the tongue. Which word describes this type of reaction? A combustion B crystallisation C endothermic D exothermic

1 marks

Answer: C

This question in 0653/11 May/June 2015

19 A student measures the initial and final temperatures of four different reactions. Which reaction is endothermic? initial final temperature / °C temperature / °C A 2 20 B 20 20 C 22 42 D 30 27

1 marks

Answer: D

This question in 0653/12 May/June 2015

19 Which change must take place in an endothermic reaction? A Bubbles of gas are released. B The mass decreases. C The temperature decreases. D The temperature increases.

1 marks

Answer: C

This question in 0653/13 May/June 2015

19 The diagram shows a platinum wire being used to catalyse the reaction between hydrogen and oxygen. platinum wire gas jar mixture of hydrogen and oxygen An explosive squeak is heard. Which statement is correct? A An acidic gas is formed. B Energy is released. C Hydrogen is reduced. D Platinum is oxidised.

1 marks

Answer: B

This question in 0653/11 Oct/Nov 2015

19 Four different solids are added to water. The initial and final temperatures are recorded. Which change is the most exothermic? initial final temperature temperature / °C / °C A 19 30 B 20 25 C 22 18 D 25 14

1 marks

Answer: A

This question in 0653/12 Oct/Nov 2015

19 Hydrochloric acid is slowly added to sodium hydroxide in an insulated beaker. The reaction is exothermic. Which graph shows how the temperature changes during the reaction? A B temperature / °C temperature / °C volume of volume of acid / cm3 acid / cm3 C D temperature / °C temperature / °C volume of volume of acid / cm3 acid / cm3

1 marks

Answer: A

This question in 0653/13 Oct/Nov 2015

18 What happens during all endothermic changes? A A gas is produced. B Solids melt. C The temperature decreases. D There is a colour change.

1 marks

Answer: C

This question in 0653/11 May/June 2016

18 Solid sodium carbonate is added to vinegar in a beaker and stirred. sodium carbonate beaker vinegar watch glass water The water in the watch glass freezes. Which statement about the reaction explains why the water freezes? A It is a redox reaction. B It is an endothermic reaction. C It is catalysed by sodium carbonate. D It is thermal decomposition.

1 marks

Answer: B

This question in 0653/12 May/June 2016

18 Which temperature changes occur during exothermic and endothermic reactions? exothermic endothermic A decreases increases B decreases no change C increases decreases D increases no change

1 marks

Answer: C

This question in 0653/13 May/June 2016

20 Solid calcium oxide reacts with cold water forming calcium hydroxide. As the cold water is added, steam is seen coming from the solid. Which statement describes the reaction? A It is endothermic and the temperature decreases. B It is endothermic and the temperature increases. C It is exothermic and the temperature decreases. D It is exothermic and the temperature increases.

1 marks

Answer: D

This question in 0653/11 Oct/Nov 2016

20 The reaction between calcium oxide and water is used to heat food in special food cans. Which type of reaction occurs? A endothermic B exothermic C neutralisation D precipitation

1 marks

Answer: B

This question in 0653/12 Oct/Nov 2016

20 Which reaction is most endothermic? initial temperature final temperature / °C / °C A 18 23 B 19 18 C 20 22 D 21 19

1 marks

Answer: D

This question in 0653/13 Oct/Nov 2016

20 Solid ammonium nitrate is soluble in water. When a large quantity of ammonium nitrate is added to water, the water freezes. Which statement describes this change? A an endothermic chemical change B an endothermic physical change C an exothermic chemical change D an exothermic physical change

1 marks

Answer: B

This question in 0653/12 Feb/March 2017

18 The diagram shows how the temperature change is measured when magnesium powder reacts with dilute hydrochloric acid. magnesium powder dilute hydrochloric acid Thermometer reading before adding magnesium powder = 20.6 °C Thermometer reading after adding magnesium powder = 32.4 °C Which statement is correct? A The reaction is endothermic and gives out heat. B The reaction is endothermic and takes in heat. C The reaction is exothermic and gives out heat. D The reaction is exothermic and takes in heat.

1 marks

Answer: C

This question in 0653/11 May/June 2017

18 The diagram shows how the temperature change is measured when magnesium powder reacts with dilute hydrochloric acid. magnesium powder dilute hydrochloric acid Thermometer reading before adding magnesium powder = 20.6 °C Thermometer reading after adding magnesium powder = 32.4 °C Which statement is correct? A The reaction is endothermic and gives out heat. B The reaction is endothermic and takes in heat. C The reaction is exothermic and gives out heat. D The reaction is exothermic and takes in heat.

1 marks

Answer: C

This question in 0653/12 May/June 2017

18 The diagram shows how the temperature change is measured when magnesium powder reacts with dilute hydrochloric acid. magnesium powder dilute hydrochloric acid Thermometer reading before adding magnesium powder = 20.6 °C Thermometer reading after adding magnesium powder = 32.4 °C Which statement is correct? A The reaction is endothermic and gives out heat. B The reaction is endothermic and takes in heat. C The reaction is exothermic and gives out heat. D The reaction is exothermic and takes in heat.

1 marks

Answer: C

This question in 0653/13 May/June 2017

19 The diagram shows gas X burning and heating a liquid. Which row is correct? gas X 0 Oo WwW > gas X hydrogen hydrogen oxygen oxygen the burning of gas X is exothermic x < x liquid flame

1 marks

Answer: A

This question in 0653/11 Oct/Nov 2017

19 The diagram shows gas X burning and heating a liquid. Which row is correct? gas X 0 Oo WwW > gas X hydrogen hydrogen oxygen oxygen the burning of gas X is exothermic x < x liquid flame

1 marks

Answer: A

This question in 0653/12 Oct/Nov 2017

19 The diagram shows gas X burning and heating a liquid. Which row is correct? gas X 0 Oo WwW > gas X hydrogen hydrogen oxygen oxygen the burning of gas X is exothermic x < x liquid flame

1 marks

Answer: A

This question in 0653/13 Oct/Nov 2017

20 Which change must take place in an endothermic reaction? A Bubbles of gas are released. B The mass decreases. C The temperature decreases. D The temperature increases.

1 marks

Answer: C

This question in 0653/11 May/June 2018

20 Which change must take place in an endothermic reaction? A Bubbles of gas are released. B The mass decreases. C The temperature decreases. D The temperature increases.

1 marks

Answer: C

This question in 0653/12 May/June 2018

20 Which change must take place in an endothermic reaction? A Bubbles of gas are released. B The mass decreases. C The temperature decreases. D The temperature increases.

1 marks

Answer: C

This question in 0653/13 May/June 2018

18 The temperature of aqueous copper sulfate is measured. After three minutes, magnesium is stirred into the solution. The temperature of the mixture is recorded every minute. The results are shown. 60 50 40 temperature / °C 30 20 10 0 0 3 6 9 12 15 18 21 24 27 30 33 36 39 42 45 48 time / minutes Which description of the chemical reaction is correct? A endothermic then exothermic B endothermic only C exothermic then endothermic D exothermic only

1 marks

Answer: D

This question in 0653/11 Oct/Nov 2018

26 Gasoline is a hydrocarbon fuel obtained from petroleum. Which statement is correct? A Gasoline burns to form carbon dioxide and water. B Gasoline contains the elements carbon, hydrogen and oxygen. C Gasoline is used as a fuel in diesel engines. D The combustion of gasoline is an endothermic reaction.

1 marks

Answer: A

This question in 0653/11 Oct/Nov 2018

19 Sodium chloride dissolves in water in an endothermic process. When calcium chloride dissolves in water, the temperature increases. Which statement is correct? A The process of dissolving calcium chloride is neither exothermic nor endothermic. B The temperature increases when sodium chloride dissolves. C The temperature remains constant when sodium chloride dissolves. D When calcium chloride dissolves in water the process is exothermic.

1 marks

Answer: D

This question in 0653/12 Oct/Nov 2018

19 Equal masses of four different solids are separately dissolved in 100 cm3 of water. The temperature of the water is recorded before the solid is added and then after the solid has dissolved. Which solid dissolves with the largest endothermic change? initial temperature final temperature / °C / °C A 18 15 B 18 22 C 19 15 D 20 26

1 marks

Answer: C

This question in 0653/13 Oct/Nov 2018

18 Four statements about reactions are listed. 1 Burning a fuel is an exothermic reaction. 2 Endothermic reactions heat up the surroundings. 3 Endothermic reactions take in energy. 4 When exothermic reactions take place the reactants gain energy. Which statements are correct? A 1 and 2 B 1 and 3 C 2 and 4 D 3 and 4

1 marks

Answer: B

This question in 0653/12 Feb/March 2019

18 The temperatures at the start and at the end of four chemical reactions are shown. Which reaction is the most exothermic? temperature at start temperature at end of reaction / °C of reaction / °C A 10 30 B 15 14 C 18 35 D 20 18

1 marks

Answer: A

This question in 0653/13 May/June 2019

19 A piece of magnesium ribbon is added to dilute hydrochloric acid at 20 °C. The mixture starts to fizz and the temperature rises to 32 °C. The fizzing then stops and the temperature slowly decreases until it reaches 20 °C. The temperature then remains constant. Which statement is correct? A The reaction is endothermic. B The reaction is exothermic. C There is an endothermic reaction followed by an exothermic reaction. D There is an exothermic reaction followed by an endothermic reaction.

1 marks

Answer: B

This question in 0653/11 Oct/Nov 2019

19 The initial and the final temperatures of four different reactions are recorded. Which reaction is the most exothermic? initial temperature final temperature / °C / °C A 19 16 B 20 19 C 22 24 D 24 25

1 marks

Answer: C

This question in 0653/12 Oct/Nov 2019

19 The initial and the final temperatures of four different reactions are recorded. Which reaction is the most exothermic? initial temperature final temperature / °C / °C A 19 16 B 20 19 C 22 24 D 24 25

1 marks

Answer: C

This question in 0653/13 Oct/Nov 2019

18 What happens during all endothermic changes? A A gas is produced. B Solids melt. C The temperature decreases. D There is a colour change.

1 marks

Answer: C

This question in 0653/12 Feb/March 2020

20 Solid sodium carbonate is added to vinegar in a beaker and stirred. sodium carbonate beaker vinegar watch glass water The water in the watch glass freezes. Which statement about the reaction explains why the water freezes? A It is a redox reaction. B It is an endothermic reaction. C It is catalysed by sodium carbonate. D It is thermal decomposition.

1 marks

Answer: B

This question in 0653/11 May/June 2020

19 Which temperature changes occur during exothermic and endothermic reactions? exothermic endothermic A decreases increases B decreases no change C increases decreases D increases no change

1 marks

Answer: C

This question in 0653/11 Oct/Nov 2020

19 Which temperature changes occur during exothermic and endothermic reactions? exothermic endothermic A decreases increases B decreases no change C increases decreases D increases no change

1 marks

Answer: C

This question in 0653/12 Oct/Nov 2020

19 Which temperature changes occur during exothermic and endothermic reactions? exothermic endothermic A decreases increases B decreases no change C increases decreases D increases no change

1 marks

Answer: C

This question in 0653/13 Oct/Nov 2020

17 Which word is used to describe a reaction that takes in heat energy from the surroundings? A endothermic B exothermic C oxidation D reduction

1 marks

Answer: A

This question in 0653/12 Feb/March 2021

20 A salt is added to water. The temperature of the water is measured before the salt is added and after it has dissolved completely. initial temperature final temperature / C / C 22 15 What is this process? A condensation B crystallisation C an endothermic change D an exothermic change

1 marks

Answer: C

This question in 0653/11 Oct/Nov 2021

20 Which row shows what happens during an endothermic reaction? reaction mixture temperature thermal energy transfer A decreases from the surroundings B decreases to the surroundings C increases from the surroundings D increases to the surroundings

1 marks

Answer: A

This question in 0653/11 May/June 2022

20 Which statements describe an endothermic reaction? 1 Energy is given out. 2 Energy is taken in. 3 The temperature of the reaction mixture decreases. 4 The temperature of the reaction mixture increases. A 1 and 3 B 1 and 4 C 2 and 3 D 2 and 4

1 marks

Answer: C

This question in 0653/12 May/June 2022

20 Which change occurs during an endothermic reaction? A The mass of a solid changes from 2.0 g to 2.5 g. B The pH of a mixture changes from 5 to 7. C The temperature of a mixture changes from 22 C to 18 C. D The volume of a gas changes from 2.0 dm3 to 1.0 dm3.

1 marks

Answer: C

This question in 0653/13 May/June 2022

17 Two chemical reactions are carried out. In reaction 1, the temperature of the reaction mixture increases. In reaction 2, energy is released by the reaction mixture. Which reactions are exothermic? A both reaction 1 and reaction 2 B reaction 1 only C reaction 2 only D neither reaction 1 nor reaction 2

1 marks

Answer: A

This question in 0653/11 Oct/Nov 2022

17 The initial and final temperature of four different reaction mixtures are measured. Which row identifies the most exothermic reaction? initial temperature final temperature / C / C A 20 25 B 21 17 C 22 12 D 23 26

1 marks

Answer: A

This question in 0653/12 Oct/Nov 2022

17 The initial and final temperature of four different reaction mixtures are measured. Which row identifies the most exothermic reaction? initial temperature final temperature / C / C A 20 25 B 21 17 C 22 12 D 23 26

1 marks

Answer: A

This question in 0653/13 Oct/Nov 2022

16 A student measures the initial temperature and the final temperature in four different reactions. Which row shows the results for the most endothermic reaction? initial final temperature temperature / C / C A 19 29 B 20 16 C 22 17 D 22 26

1 marks

Answer: C

This question in 0653/12 Feb/March 2023

19 Which reactions are exothermic? 1 a reaction that gets cooler 2 a reaction that gives out energy 3 a reaction that takes in energy 4 the combustion of methane A 1 and 2 B 1 and 3 C 2 and 4 D 3 and 4

1 marks

Answer: C

This question in 0653/11 May/June 2023

19 The initial and final temperatures of four different reactions are measured. The results are shown. Which reaction is the most exothermic? initial final temperature temperature / C / C A 21 18 B 21 27 C 23 28 D 24 17

1 marks

Answer: B

This question in 0653/12 May/June 2023

19 Powdered zinc reacts with a blue solution of copper(II) sulfate. Which observation shows that the reaction is exothermic? A A red-brown solid forms. B Some grey solid remains after the reaction. C The blue colour of the solution fades. D The temperature increases.

1 marks

Answer: D

This question in 0653/13 May/June 2023

17 Which process is endothermic? A boiling water B burning wood C freezing water D neutralising an acid with a base

1 marks

Answer: A

This question in 0653/11 Oct/Nov 2023

17 When solid sodium carbonate and dilute hydrochloric acid are mixed, a reaction occurs. During this reaction, carbon dioxide is released and the temperature of the mixture increases. Which chemical terms describe this reaction? 1 exothermic 2 neutralisation 3 thermal decomposition A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

1 marks

Answer: B

This question in 0653/12 Oct/Nov 2023

17 When solid sodium carbonate and dilute hydrochloric acid are mixed, a reaction occurs. During this reaction, carbon dioxide is released and the temperature of the mixture increases. Which chemical terms describe this reaction? 1 exothermic 2 neutralisation 3 thermal decomposition A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

1 marks

Answer: B

This question in 0653/13 Oct/Nov 2023

17 Sodium chloride dissolves in water in an endothermic process. When calcium chloride dissolves in water, the temperature of the solution increases. Which statement is correct? A The process of dissolving calcium chloride is neither exothermic nor endothermic. B The temperature of the solution increases when sodium chloride dissolves. C The temperature of the solution remains constant when sodium chloride dissolves. D When calcium chloride dissolves in water, the process is exothermic.

1 marks

Answer: D

This question in 0653/12 Feb/March 2024

19 Which row describes an exothermic reaction? temperature of the direction of reaction mixture energy transfer A decreases from the surroundings B decreases to the surroundings C increases from the surroundings D increases to the surroundings

1 marks

Answer: D

This question in 0653/12 May/June 2024

17 Which type of reaction always releases thermal energy into the surroundings? A endothermic B evaporation C exothermic D redox

1 marks

Answer: C

This question in 0653/11 Oct/Nov 2024

18 The initial temperature of a sample of water is measured. Ammonium nitrate is mixed with the water. The final temperature is measured. The diagram shows the thermometer readings. 21 19 20 18 initial temperature final temperature Which row shows the initial temperature, the final temperature and the type of reaction that occurs? initial final type of temperature temperature reaction / °C / °C A 20.4 18.7 endothermic B 20.4 18.7 exothermic C 21.6 19.3 endothermic D 21.6 19.3 exothermic

1 marks

Answer: A

This question in 0653/11 May/June 2025

19 Which reaction is most endothermic? initial temperature final temperature / °C / °C A 21 19 B 20 22 C 19 18 D 18 23

1 marks

Answer: A

This question in 0653/12 May/June 2025

18 Magnesium ribbon is added to dilute hydrochloric acid at 20 °C. The mixture starts to fizz and the temperature increases to 32 °C. The fizzing then stops and the temperature slowly decreases until it reaches 20 °C. The temperature then remains constant. Which statement is correct? A The reaction is endothermic. B The reaction is exothermic. C There is an endothermic reaction followed by an exothermic reaction. D There is an exothermic reaction followed by an endothermic reaction.

1 marks

Answer: B

This question in 0653/13 May/June 2025

16 The initial and the final temperatures of four different reactions are recorded. Which reaction is the most exothermic? initial temperature final temperature / °C / °C A 19 16 B 20 19 C 22 24 D 24 25

1 marks

Answer: C

This question in 0653/12 Oct/Nov 2025

16 The initial and the final temperatures of four different reactions are recorded. Which reaction is the most exothermic? initial temperature final temperature / °C / °C A 19 16 B 20 19 C 22 24 D 24 25

1 marks

Answer: C

This question in 0653/13 Oct/Nov 2025