C7: Energy Changes

Question 1

Energy is _____ in chemical reactions. It is neither created or destroyed

Answer 1

Conserved

Question 2

What is an exothermic reaction?

Answer 2

A reaction in which energy is transferred from the reacting substances to thier SURROUNDINGS

Question 3

What is an endothermic reaction?

Answer 3

A reaction where energy is transferred to the reacting substancws from their surroundings

Question 4

What can endothermic changes be used in?

Answer 4

Instant cold packs for sport injuries

Question 5

What can exothermic changes be used in?

Answer 5

Hand warmers and self-heating cans

Question 6

Bond making is ______

Answer 6

Exothermic

Question 7

Bond breaking is_______

Answer 7

Endothermic

Question 8

What is activation energy?

Answer 8

The minimum amount of energy needed before colliding particles have sufficient energy to causs a reaction

Question 9

In chemical reactions, energy must be supplied to _________

Answer 9

Break the bonds between atoms in the reactants

Question 10

When new bonds are formed between atoms in a chemical reaction what is released?

Answer 10

Energy

Question 11

Describe an exothermic reaction

Answer 11

Energy released when new bonds are formed>energy absorbed when bonds are broken

Question 12

Describe an endothermic reaction

Answer 12

Energy formed when new bonds are made

Question 13

How can you calculate the overall energy change in a rection

Answer 13

Using bond energies

Question 14

How are exothermic changes used?

Answer 14

Hand warmers and self heating cans

Question 15

How are endothermic reactions used?

Answer 15

-instant cold packs for sports injuries