Exam 3

Question 1

The change in concentration of a reactant or product per unit time

Answer 1

Reaction rate

Question 2

The slope of the line joining two points along the curve over a given period of time

Answer 2

Average reaction rate

Question 3

The rate of a reaction at a specific instant

Answer 3

Instantaneous reaction rate

Question 4

The instantaneous rate at the moment reactants are mixed

Answer 4

Initial reaction rate (t=0)

Question 5

What is the general rate law?

Answer 5

Rate=k[A]^m[B]^n

Question 6

A mathematical equation that describes how the rate of a reaction depends upon the concentrations of each reactant

Answer 6

Rate Law

Question 7

The power to which the concentration of a reactant is raised in a rate law expression for a reaction

Answer 7

Reaction Order

Question 8

The proportionality constant that relates the rate of a reaction to the concentration of reactants, at a given temperature

Answer 8

Rate Constant

Question 9

What is the rate equation for the general reaction aA–>Product that is a first order reaction?

Answer 9

Rate = -Δ[A]/Δt = k[A]^n

Question 10

A mathematical expression that describes the change in concentration of a reactant in a chemical reaction with time

Answer 10

Integrated rate law

Question 11

What is the integrated rate law for a first order reaction?

Answer 11

ln[A]=lnA - kt

Question 12

What is the integrated rate law for a second order reaction?

Answer 12

1/[A]=1/A + kt

Question 13

What is the integrated rate law for a zero order reaction?

Answer 13

[A]=A - kt

Question 14

The time it takes for the reactant concentration to reach half of its initial value

Answer 14

Half-life

Question 15

What is the half-life equation for a first order reaction?

Answer 15

t1/2=ln2/k or t1/2=0.693/k

Question 16

What is the half-life equation for a second order reaction?

Answer 16

t1/2=1/kA

Question 17

What is the half-life equation for a zero order reaction?

Answer 17

t1/2=A/2k

Question 18

The minimum amount of energy required to initiate a chemical reaction and is specific to a particular reaction

Answer 18

Activation energy, Ea

Question 19

Shows temperature dependence of the rate constant, k

Answer 19

Arrhenius Equation: k=Ae(-Ea/RT)

Question 20

What equation would you use to determine activation energy?

Answer 20

ln k = -Ea/RT +ln A

Question 21

The individual steps that make up a reaction mechanism

Answer 21

Elementary reactions

Question 22

The number of reactant particles involved in an elementary step

Answer 22

Molecularity

Question 23

What are the 3 criteria for proposing a mechanism?

Answer 23

1. ) The elementary steps must add up to the overall balanced equation
2. ) The elementary steps must be reasonable
3. ) Rate limiting must have the same rate law as that determined from experimental data

Question 24

Provides an alternative route for the reaction with a lower activation energy

Answer 24

Catalyst