Chapter 13

Question 1

Collision Theory

Answer 1

Used to predict the rates of reactions and is based upon the idea that molecules must collide with enough kinetic energy and the correct 3D orientation in order to react and form bonds

The higher frequency of collins, the faster the reaction rate

Question 2

Activation Energy (Ea)

Answer 2

The minimum amount of energy required for a reaction to commence

Energy between the reactant and the transition state

Ea is always POSITIVE

Question 3

Exothermic

Answer 3

• Reactant > Product
• Delta H is always negative
• Process gives off heat
• “EXIT”

Question 4

Endothermic

Answer 4

• Energy of products > reactants
• Delta H is positive
• Process consumes heat
• “ENTER”

Question 5

Transition state

Answer 5

Maximum energy, aka activated complex

Question 6

Rate

Answer 6

• A rate of change will always be negative for any reactant since reactants are consumed over time
• The larger a reactant or product’s stiometric, the greater the rate of change of its concentration
• The larger the stoichiometric coefficient, the faster the rate of change of a reactant or product concentrations

Question 7

Rate Laws

Answer 7

• The higher the frequency of molecular collisions, the faster the rate reaction
• The higher the pressure, the higher frequency of molecular collisions=the faster the rate of reaction
• Reaction rate is directly proportional to reactant concentration
• Depends on the rate of REACTANT (not product)
• K is the rate constant, always a positive value
• X and Y are the reaction orders
• The sum of individual reaction orders equals the overall order of the reaction
• Order include: Zero, first, second, third

Question 8

Rate Constant

Answer 8

0 order units of k = M+^1 x s^-1
1 order units of k = s^-1
2 order units of k = M+^-1 x s^-1
3 order units of k = M+^-2 x s^-1

Question 9

Arrhenius equation

Answer 9

A= frequency factor
E=activation energy
R=ideal gas constant= 8.314 J/ mol K
K=rate constant
T=temp

Question 10

The concentration of reactant changes …

Answer 10

The concentration of reactant changes changes the reaction rate, but not the rate constant

Question 11

A catalyst results in a large

Answer 11

rate constant K

Question 12

An increase in temperature almost always

Answer 12

Increases K