Topic 9: Kinetics and Equilibrium

Question 1

Collision theory

Answer 1

a reaction is most likely to occur when the reactant particles collide with proper ENERGY and ORIENTATION

Question 2

The rate of a chemical reaction depends on what?

Answer 2

1. temp- direct
2. concentration- direct
3. surface area- direct
4. presence of a catalyst- direct
   direct relationships mean that increasing all of these factors will increase the rate of reaction

Question 3

equilibrium

Answer 3

-rate of forward reaction=rate of reverse reaction
-quantities of reactants and products remain CONSTANT

Question 4

LeChatelier’s principle

Answer 4

used to predict effect of stress on a system in equilibrium
-stresses=change in pressure, volume, concentration, temp

Question 5

What do potential energy diagrams present?

Answer 5

the energy absorbed or released by the chemical reaction

Question 6

Heat of Reaction

Answer 6

amount of energy released or absorbed
-equals (PE of products-PE of reactants)
-a positive heat of reaction implies ENDOthermic
-a negative heat of reaction implies EXOthermic

Question 7

A catalyst will..

Answer 7

-increase rate of reaction (forward and reverse equally)
-not shift equilibrium
-require a LOWER activation energy than the uncatalyzed reaction
-provide an alternative pathway for this chem. reaction

Question 8

entropy

Answer 8

measure of randomness or disorder

Question 9

enthalpy

Answer 9

measure of energy

Question 10

systems in nature tend to lead to ____enthalpy and ____entropy

Answer 10

LOWER enthalpy
HIGHER entropy

Question 11

Are exothermic reactions that result in HIGHER entropy spontaneous or nonsponaneous?

Answer 11

SPONTANEOUS, as systems of nature tend to lead to lower enthalpy (heat is energy) and higher entropy (randomness)