Chapter 8

Question 1

The plot of ln [A] vs. time is linear for a ____ order reaction.

For second order reaction,_______ is linear.

For a zero order reaction,____ varies linearly with time.

The rate constant is the absolute value of the slope of the _____ _____ ____ _____

Answer 1

first, 1/[A], [A]

best line of fit

Question 2

Which of the following statements is true regarding a first order reaction?

A. The half-life of a first order reaction increases with increasing initial concentration of the reactant.

B. The half-life is dependent of the initial concentration of the reactant.

C. The half-life is independent of the initial concentration of the reactant.

D. The rate constant of a first order reaction increases with time.

E. The rate of a first order reaction increases with time.

Answer 2

C

Question 3

What are the units for zero, first, second, and third order?

Answer 3

zero: M1 x s1
first: s-1
second: M-1 x S-1
third: M-2 x s-1

Question 4

What components of the rate law must be determined experimentally?

What does not appear in the rate law?

Answer 4

M and n

products

Question 5

Describe the relationships between half life and concentration for zero, first, and second order

Answer 5

zero - half life and concentration are inversely related

first = half life is independent of the concentration

second = half life and concentration are inversely related

Question 6

Identify where enthalpy and transition state are found on a reaction coordinate diagram

If reactants are higher than the products in the diagram, what kind of reaction is it? Vice versa?

Answer 6

enthalpy - space between reactants and products

transition state - humps

if the reactants are higher than the products, this means that the reaction is exothermic, meaning it will release energy

If reactants are lower than the products, the reaction is endothermic = absorb energy

Question 7

How do you find the rate determining step on a reaction coordinate diagram?

Answer 7

find the hump with the largest activation energy

Question 8

Catalysts are present in both the ____ and ____ of a reaction because they do not get ______.

Answer 8

reactants, products, consumed

Question 9

T/F - Catalysts will lower activation energy to reach equilibrium faster by shifting equilibrium reactions and changing energy levels.

Answer 9

FALSE

Question 10

Collision Theory

Answer 10

1 - both molecules must collide
2 - both need to collide with as much energy for the reaction to happen; ie overcome Ea
3 - neet to collide with correct 3D orientation

Question 11

Describe the relationship between Ea and reaction rate

Answer 11

Ea and reaction rate are inversely related