Energy Change in Reactions

Question 1

Heat of Reaction (delta H)

Answer 1

The net change of chemical potential energy of the system

Question 2

Exothermic reactions

Answer 2

Reactions which transfer potential energy into thermal energy

Question 3

Endothermic reactions

Answer 3

Reactions which transfer thermal energy into potential energy

Question 4

Endothermic processes

Answer 4

Involve bond breaking

Question 5

Exothermic processes

Answer 5

Involve bond formation

Question 6

Exothermic reaction bond

Answer 6

These bonds are stronger than the bond being broken

Question 7

Endothermic reaction bond

Answer 7

These bonds are weaker than the bond being broken

Question 8

Stronger bonds when broken

Answer 8

Requires more energy to break

Question 9

Stronger bonds when formed

Answer 9

Release more energy when formed.

Question 10

delta H > 0

Answer 10

Endothermic rxt’s

Question 11

delta H < 0

Answer 11

Exothermic rxt’s

Question 12

Activation energy

Answer 12

The minimum energy required to start a chemical reaction

Question 13

Collision Theory

Answer 13

Colliding particles must have, apart from the correct orientation, a kinetic energy equal to or bigger than the activation energy of a reaction before the reaction can take place

Question 14

Activated Complex

Answer 14

A temporary transition state between the reactants and the products