Energy Changes

Question 1

Exothermic reaction

Answer 1

Transfers energy to surroundings usually by heating

Shown by rise in temperature

Question 2

Endothermic reaction

Answer 2

Takes in energy from surroundings

Shown by fall in temperature

Question 3

Uses of exothermic reactions

Answer 3

Hand warmers

Self heating cans of coffee

Question 4

Use of endothermic reactions

Answer 4

Sports injury packs

Question 5

How can energy transfer be measured?

Answer 5

Taking temperature of reagents, mixing them in polystyrene cup and measuring temperature of solution at end of reaction

Question 6

Problem with energy measurements?

How can you solve this?

Answer 6

Amount of energy lost to surroundings

Put polystyrene cup into a beaker of cotton wool to give more insulation + a lid to reduce energy lost by evaporation

Question 7

Bond breaking

Answer 7

Endothermic

Question 8

Bonding formation

Answer 8

Exothermic

Question 9

What does a reaction profile show?

Answer 9

Energy changes

Question 10

Exothermic reaction profile

Answer 10

Products at lower energy than reactants

Question 11

Endothermic reaction profile

Answer 11

Products at higher energy than reactants