Energy Changes Chemistry

Question 1

What is an exothermic reaction?

Answer 1

A reaction that causes a rise in temperature to surroundings- it releases energy

Question 2

What is an endothermic reaction?

Answer 2

A reaction that causes a decrease in temperature in the surroundings-it takes in energy

Question 3

What happens in a chemical reaction?

Answer 3

Atoms are rearranged as old bonds are broken and new bonds are formed

Question 4

What must happen for bonds to be broken in a chemical reaction?

Answer 4

Reacting particles must collide with sufficient energy

Question 5

What is the activation energy?

Answer 5

The minimum amount of energy that particles must have to take placel

Question 6

Why does an exothermic reaction graph have that shape?

Answer 6

Because energy is given out to the surroundings and the products have less energy than the reactants

Question 7

Why does an endothermic reaction graph has that shape?

Answer 7

Because energy is taken in from the surroundings and the products have more energy than the surroundings

Question 8

Is breaking a bond in a chemical reaction an endothermic or exothermic process?

Answer 8

Endothermic

Question 9

Is forming a bond in a chemical reaction an endothermic or exothermic process?

Answer 9

Exothermic

Question 10

What determines if a reaction is exothermic?

Answer 10

If the energy released when bonds are formed is greater than the energy needed to break bonds

Question 11

What determines if a reaction is endothermic?

Answer 11

If the energy needed to break bonds is more than the energy released as bonds formed