AQA Combined Chemistry 5.5

Question 1

Name the type of reaction that is used in sports injury packs

Answer 1

Endothermic reaction

Question 2

Name the type of reaction that is used in self-heating cups and hand warmers

Answer 2

Exothermic reaction

Question 3

What is the name for the minimum amount of energy needed for a reaction to happen?

Answer 3

Activation energy

Question 4

Complete the sentences; In a chemical reaction:
A) Energy is needed to _________
B) Energy is released when______

Answer 4

A) Energy is needed to break bonds

B) Energy is released when bonds are formed

Question 5

Explain, in terms of bonds and energy, what makes a reaction;
A) Exothermic
B) Endothermic

Answer 5

A) Exothermic - energy released from forming new bonds is greater than the energy needed to break existing bonds
B) Endothermic - energy needed to break existing bonds is greater than the energy released when new bonds are formed

Question 6

Give an example of a chemical reaction that is exothermic

Answer 6

Combustion, Oxidation or Neutralisation

Question 7

Name the following reactions that:
A) Take in heat from the surroundings
B) Give out heat to the surroundings

Answer 7

A) Endothermic

B) Exothermic

Question 8

What can be said about the amount of energy before a chemical reaction and the amount of energy after a chemical reaction?

Answer 8

They are equal

Question 9

Give an example of a chemical reaction that is endothermic

Answer 9

Thermal Decomposition and Reacting Citric Acid with Sodium hydrogencarbonate