C7 Energy Changes

Question 1

1. What is the name given to reactions that take in energy?

Answer 1

1. Endothermic

Question 2

2. What is the name given to reactions that give out energy?

Answer 2

2. Exothermic

Question 3

3. In exothermic reactions what has more energy – the product or the reactant?

Answer 3

3. Reactant

Question 4

4. In an exothermic reaction what happens to the temperature of the surroundings?

Answer 4

4. Increases

Question 5

5. What is an example of an exothermic reaction?

Answer 5

5. Combustion, oxidation, neutralisation

Question 6

6. What is an example of an endothermic reaction?

Answer 6

6. Thermal decomposition

Question 7

7. Draw the reaction profile for an exothermic reaction.

Label the activation energy and total energy change.

Answer 7

Reactants need to be higher than the products. The Activation energy is the energy from the reactants up to the peak and the energy change is the difference in energy between the reactants and products.

Question 8

8. What is the activation energy?

Answer 8

8. Minimum energy particles must have to start a reaction.