Physical Chapter 5: Kinetics, Equilibria, and Redox

Question 1

What is reaction rate defined as?

Answer 1

The amount of reactant used or product formed over time

Question 2

What is Collision theory?

Answer 2

The idea that particles have to collide with a sufficient amount of kinetic energy in order to react

Question 3

What is Activation energy?

Answer 3

The minimum amount of energy needed for particles to react

Question 4

What is the Maxwell-Boltsman distribution?

Answer 4

A graph showing the distribution of molecules at certain energy levels

Question 5

What does the area under the Maxwell-Boltsman curve represent?

Answer 5

The total number of molecules

Question 6

What is the effect of increasing temperature on reaction rate?

Answer 6

Rate will increase

Question 7

Why does increasing temperature increase rate of reaction?

Answer 7

Each molecule will have greater energy and therefore more will meet the activation energy.

Question 8

What is the effect of increased concentration on rate of reaction?

Answer 8

It will increase the rate

Question 9

What is the effect of increased pressure on rate of reaction?

Answer 9

It will increase the rate

Question 10

What is the effect of a catalyst on rate of reaction?

Answer 10

It provides an alternate pathway for the reaction with a loer activation energy - rate will increase

Question 11

What are the three main ways to measure reaction rates?

Answer 11

Time taken for a precipitate to form
Measuring a decrease in mass
Measuring volume of gas given off

Question 12

What is a reversible reaction?

Answer 12

A reaction that can go either way

Question 13

What is dynamic equilibrium?

Answer 13

All products and reactants’ concentrations stay constant

Question 14

What is Le Chatelier’s principle?

Answer 14

If a reaction at equilibirum is subjected to a change, the position of equilibrium will move to counter that change.

Question 14

What is Le Chatelier’s principle?

Answer 14

If a reaction at equilibirum is subjected to a change, the position of equilibrium will move to counter that change.

Question 14

What is Le Chatelier’s principle?

Answer 14

If a reaction at equilibirum is subjected to a change, the position of equilibrium will move to counter that change.

Question 15

What will happen if you increase the temperature of an equilibrium mixture?

Answer 15

The position of Equilibrium will move in the endothermic direction

Question 16

What will happen if you increase the concentration of a product in an equilibrium mixture?

Answer 16

The position of equilibrium will move to the left to produce more reactant

Question 17

What will happen if you increase the pressure of an equilbrium mixture?

Answer 17

The position of equilbrium will move towards the side with less molecules

Question 18

What effect do catalysts have on position of equilibrium?

Answer 18

None

Question 19

What affects how reaction conditions are chosen in industry?

Answer 19

Compromise between speed, yield, and cost of production

Question 20

What is the Equilibrium constant written as?

Answer 20

K_c

Question 21

What is the formula for K_c?

Answer 21

Where aA + bB <-> cC + dD,
K_c = [D]^d[C]^c/[A]^a[B]^b

Question 22

What is the only factor that affects Kc?

Answer 22

Temperature

Question 23

How does temperature affect Kc?

Answer 23

If it means there is more product at equilibrium, Kc will rise. If it means less product at Equilibrium, Kc will fall.

Question 24

What is the definition of a redox reaction?

Answer 24

Any reaction where electrons are transferred

Question 25

What is oxidation?

Answer 25

Loss of electrons

Question 26

What is reduction?

Answer 26

Gain of electrons

Question 27

What is an oxidising agent?

Answer 27

A chemical that gets reduced

Question 28

What is a reducing agent?

Answer 28

A chemical that gets oxidised

Question 29

How do you assign oxidation states?

Answer 29

Overall oxidation state is equal to the charge of the ion or compound
Oxidation state of each element is often the same as the charge on its ion (e.g. O will often be 2-)

Question 30

How do you combine half-equations?

Answer 30

Make sure the charges & electrons match