End Of Unit Questions

Question 1

How can you find the rate of reaction from a graph of mass of product against time?

Answer 1

From the gradient of the graph

Question 2

What is meant by the activation energy of a reaction?

Answer 2

The minimum energy that particles must have for collisions to produce a reaction

Question 3

Name 2 types of reactions that are exothermic

Answer 3

Combustion, oxidisation, neutralisation

Question 4

Why must calcium carbonate be heated continuously to convert it into calcium oxide and carbon dioxide?

Answer 4

Thermal decomposition is an endothermic reaction

Question 5

Nitrogen and oxygen react together to produce nitrogen oxide, what changes in conditions would increase the rate of this reaction?

Answer 5

High temp, high pressure, catalyst

Question 6

Explain in terms of particles why increasing the concentration of a reactant increases the rate of reaction

Answer 6

Particles are closer together (more particles in the same volume) so collisions are more frequent

Question 7

Explain why increasing the temp increases the rate of a reaction

Answer 7

Particles collide more frequently and with more energy so more collisions have the activation energy

Question 8

Pieces of zinc react with dilute hydrochloric acid to make zinc chloride and hydrogen gas. In what ways could you increase the rate of reaction between zinc and hydrochloric acid?

Answer 8

Increase concentration of acid, increase temp, use powdered zinc, use a catalyst