Midterm 1

Question 1

Activated complex

Answer 1

Aka. Transition state
Unstable combination of reactant species forming during a chemical reaction

Question 2

Activation energy

Answer 2

Minimum energy necessary in order for a reaction to take place

Question 3

Arrhenius equation

Answer 3

Relationship between reaction rate’s constant, activation energy, and temperature

Question 4

Average rate

Answer 4

The instantaneous rate of change over time
Change in concentration / change in time

Question 5

Bimolecular equation

Answer 5

Elementary reaction involving two reactant entities

Question 6

Catalyst

Answer 6

Substance that increases the rate of a reaction without itself being consumed by the reaction

Question 7

Collision theory

Answer 7

Model that emphasizes the energy and orientation of molecular collisions to explain and predict reaction kinetics

Question 8

Elementary reaction

Answer 8

Reaction that takes place in a single step, precisely as depicted in its chemical equation

Question 9

Frequency factor (A)

Answer 9

Proportionally constant in the Arrhenius equation, relatives to the relative number of collisions having an orientation capable of leading to product formation

Question 10

Half-life of a reaction (t1/2)

Answer 10

Time required for half a given reaction to be consumed

Question 11

Heterogeneous catalyst

Answer 11

Catalyst present in a different phase from the reactant, furnishings surface at which a reaction can occur

Question 12

Homogenous catalyst

Answer 12

Catalyst present in the same phase as the reactant

Question 13

Initial rate

Answer 13

Instantaneous rate at t=0s

Question 14

Instantaneous rate

Answer 14

Rate of a chemical reaction at any instant in time, determine by the slopes of the line tangential to a graph of concentration as a function of time

Question 15

Integrated rate law

Answer 15

Equation that relates the concentration of a reactant to elapsed time of reaction

Question 16

Intermediate

Answer 16

Entities produced in one step of a reaction mechanism and consumed in a subsequent step

Question 17

Molecularity

Answer 17

Number of reactant entities involved in an elementary reaction n

Question 18

Overall reaction order

Answer 18

Sum of the reaction orders for each substance represented in the rate law

Question 19

Rate constant (k)

Answer 19

Proportionality constant in a rate law

Question 20

Rate expression

Answer 20

Defining reaction rate as change in amount, concentration, or pressure of reactant or products species per unit time

Question 21

Rate law

Answer 21

Showing the dependence of reaction rate on the rate constant and the concentration of one or more reactants

Question 22

Rate of reaction

Answer 22

Measure of the speed at which a chemical reaction takes place

Question 23

Rate-determining step

Answer 23

• Slowest elementary reaction in a reaction mechanism
• determines rate of the overall reaction

Question 24

Reaction diagram

Answer 24

Used in chemical kinetics to illustrate various properties of a reaction

Question 25

Reaction mechanism

Answer 25

Stepwise sequence of elementary reactions by which a chemical change takes place

Question 26

Reaction order

Answer 26

Value of an exponent in a rate law

Question 27

Termolecular reaction

Answer 27

Elementary reaction involving three reactant entities

Question 28

Unimolecular reaction

Answer 28

Elementary reaction involving a single reactant entity

Question 29

Half-life for a zero-order reaction

Answer 29

T1/2 = [A]0/2k

Question 30

Integrated rate law for zero-order reactions

Answer 30

Ln [A]t = -kt + ln [A]0