Reaction Rates And Equilibrium

Question 1

How do the speeds of chemical reactions vary

Answer 1

From very fast to very slow

Question 2

Rate

Answer 2

A measure of how much something changes within a specified amount of time

Question 3

How is the amount of the reactant expressed

Answer 3

In moles

Question 4

Collision theory
What can react to form products when they collide if the particles have enough kinetic energy

Answer 4

Atoms, ions, and molecules

Question 5

Collision theory
What do particles that do not have enough energy do

Answer 5

They simply bounce off of each other unchanged

Question 6

Reaction energy

Answer 6

The minimum energy that colliding particles must have in order to react
Barrier reactants must cross to form products

Question 7

When two reactant particles collide they may form what

Answer 7

An activated complex, to transition state.
Is an unstable arrangement of atoms that forms for a moment at peak of the activation energy barrier

Question 8

Raising the temperature does what to reaction rate

Answer 8

Usually speeds up the reaction. The particles move faster, the frequency of collision increases; and how fast the product forms

Question 9

Lowering temperature does what to reaction rate

Answer 9

Usually slows down a reaction. Particles move slower, frequency of collision decreases; how fast the product forms slows down

Question 10

Increasing concentration does what to speed?
Decreasing concentration does what to speed?

Answer 10

Increasing concentration increases speed and decreasing concentration decreases speed

Question 11

Bigger particle size does what
Smaller particle size does what

Answer 11

Slower reaction rate
Faster reaction rate

Question 12

Ways to increase surface area

Answer 12

Dissolve particles in a solution
Grind particles into a powder

Question 13

Catalyst

Answer 13

A catalyst is a substance that increase the rate of a reaction without being used up during the reaction

Question 14

What do inhibitors interfere with

Answer 14

Inhibitor interfere with the action of a catalyst

Question 15

K is at a constant rate and is?

Answer 15

Different for every reaction
Large if the products form quickly >1
Small if the products form slowly <1
The expression Rate= K[A]^X is called a rate law

Question 16

The order of a reaction is what

Answer 16

The power to which a concentration of a reactant must be raised to match experimental data on concentration and rate

Question 17

The concentration of a reactant is?

Answer 17

Raised to the first power

Question 18

Elementary reaction

Answer 18

A reaction in which reactants are converted to products in a single step

Question 19

Multi-step reaction

Answer 19

A chemical reaction that consists of two or more reactions (called a reaction mechanism)

Question 20

Intermediate

Answer 20

A product of one step in a reaction mechanism and a reactant in the next step of the reactant mechanism. (Doesn’t appear in overall chemical equation for a reaction)

Question 21

Reversible reactions

Answer 21

A reversible reaction is one in which the conversion of reactants to products and the conversion of products to reactants occur at the same time

Question 22

Establishing equilibrium

Answer 22

When the rates of a forward reaction and reverse reaction are equal, you have reached equilibrium

Question 23

La Chatelier’s principle

Answer 23

If a stress is applied to a dynamic equilibrium, the system changes in a way that relieves the stress.
These stresses that upset the equilibrium include: Changes in temperature (heat added-moves in direction that absorbs heat), changes in the concentration of reactants or products, Changes in pressure

Question 24

Equilibrium constants

Answer 24

The equilibrium constant of a reaction (Keq) is the ratio of product concentrations to reactant concentrations at equilibrium
The value of (Keq) depends on the temperature of the reaction

Question 25

The size of Keq depends on what

Answer 25

Whether reactants or products are more common at equilibrium

Question 26

When finding K or Keq what should you use

Answer 26

Gases only

Question 27

Reaction rate equation

Answer 27

Rate= K [A]^1 [B]^1

Question 28

Solubility

Answer 28

The ability to be dissolved (most of the time in water)

Question 29

How many solubility rules are there

Answer 29

There are 6 solubility rules/ not all compounds are soluble

Question 30

Free energy

Answer 30

The energy that is available to work

Question 31

When can energy be obtained from a reaction

Answer 31

Only if the reaction occurs

Question 32

Some chemical reactions are spontaneous

Answer 32

1) a spontaneous reaction occurs naturally and favors the formation of products at the stated conditions
2) spontaneous reactions produce large amounts of products and release free energy

Question 33

Non spontaneous reaction

Answer 33

A chemical reaction that doesn’t favor the formation of products
- these products produce little, if any product

Question 34

Enthalpy

Answer 34

The change in heat of a reaction
(Exothermic is releases heat/ endothermic absorbs heat)

Question 35

Entropy

Answer 35

A measure of the disorder of a system
Ex: A solid has less entropy than a liquid, and a liquid has less entropy than a gas.

Question 36

The law of disorder

Answer 36

1) States that the natural tendency is for systems to move in the direction of increasing disorder or randomness.
2) Reactions in which entropy increases as reactants form products tend to be favored.
3) The size and direction of enthalpy changes and entropy changes determine whether a reaction is spontaneous