Paper 1- Unit 5a Energy and reversible reactions

Question 1

Exothermic

Answer 1

gives out energy

from the chemicals to the surroundings

Question 2

Endothermic

Answer 2

takes in energy

from the surroundings into the chemicals

Question 3

How do you measure the temperature change of a reaction?

Answer 3

Measure the temperature before

let the reaction take place

measure the temperature again

calculate the difference

Question 4

How can you experimentally determine if a reaction is exothermic or endothermic?

Answer 4

Calculate the temperature difference

Increase = exothermic

decrease= endothermic

Question 5

Minimum energy required for a reaction to occur

Answer 5

activation energy

Question 6

Activation energy

Answer 6

the minimum energy required for a reaction to occur

Question 7

All reactions require energy to…

Answer 7

break the bonds in the reactants

Question 8

Units for energy

Answer 8

Joules or Kilojoules

Question 9

Combustion is…

Answer 9

when a fuel is fully burnt in oxygen

to produce carbon dioxide and water

Question 10

Oxidation is…

Answer 10

oxygen is added to a substance

Question 11

Bond energy equation

Answer 11

Change in Energy = bonds broken - bonds made

Question 12

Bond energy- Exothermic

Answer 12

Change in Energy = bonds broken - bonds made

When bonds made is larger than bonds broken

energy change in negative

Question 13

Bond energy- endothermic

Answer 13

Change in Energy = bonds broken - bonds made

When bonds broken is larger than bonds made

energy change in positive