C8.6/7 Reversible reactions and Exothermic and Endothermic Reactions

Question 1

What happens with energy when a chemical reaction occurs? (2 marks)

Answer 1

Energy is either transferred to or from the surroundings

Question 2

What is a reversible reaction?

Answer 2

In a reversible reaction, the products can react to produce the original reactants again

Question 3

What is an exothermic reaction? (1 mark)

Answer 3

A reaction that gives out energy to the surroundings (these reactions can feel hot)

Question 4

Give some examples of exothermic reactions (3)

Answer 4

Combustion
Many oxidation reactions
Neutralisation

Question 5

What are some everyday uses of exothermic reactions?(2)

Answer 5

Self-heating cans (e.g for coffee).

Hand warmers.

Question 6

What is an endothermic reaction?(1)

Answer 6

A reaction that takes in energy from the surroundings (these reactions can feel cold)

Question 7

Give some examples of endothermic reactions(1)

Answer 7

Thermal decomposition

Question 8

What are everyday uses of endothermic reactions?(1)

Answer 8

Sports injury packs

Question 9

If a reaction is reversible and is exothermic in one direction, what will it be in the opposite direction? (1 mark)

Answer 9

Endothermic

Question 10

10. If a reaction is reversible and is endothermic in one direction, what will it be in the opposite direction? (1 mark)

Answer 10

Exothermic

Question 11

What can be said about the energy given out and the energy taken in a reversible reaction? (1 mark)

Answer 11

They are the same (If a reaction gives out 100J in one direction then it will take in 100J in the other)