Question 1

Equilibrium

Accepted Answer

a state in which there are no observable changes as time goes by.

Question 2

Chemical Equilibrium

Accepted Answer

a state in which the rates of the forward and reverse reactions are equal. The concentrations of the reactants and products remain constant.

Question 3

Physical Equilibrium

Accepted Answer

equilibrium in which only physical properties change

Question 4

equilibrium constant

Accepted Answer

K. A number equal to the ratio of the equilibrium concentrations of products to the equilibrium concentrations of reactants, each raised to the power of its stociometric coefficient

Question 5

Law of the mass action

Accepted Answer

for a reversible reaction at quilibrium and a constant temperature, a certain ratio of reactants and product concentrations has a constant value, k (the equilibrium constant)

Question 6

K>>1

Accepted Answer

lies to the right, favors products (greater then 10)

Question 7

K<<1

Accepted Answer

lies to the left, favors reactants (less then 0.1)

Question 8

Homogeneous equilibrium

Accepted Answer

all reacting species are in the same phase

Question 9

Δn

Accepted Answer

moles of gaseous products-moles of gaseous reactants= (c+d)-(a+b)

Question 10

Heterogeneous equilibrium

Accepted Answer

reactions in which reactants and products are in different phases.

Question 11

Rules for writing equilibrium constant

Accepted Answer

1. an equation for a reversal reaction is written in the opposite direction the equilibrium constant becomes the reciprocal of the original equilibrium constant
2. the value k also depends on how the equilibrium is balanced.

Question 12

reaction quotient

Accepted Answer

is calculated bu substituting the initial concentrations of the reactants and products into the equilibrium constant Kc expression

Question 13

Qc > Kc

Accepted Answer

system proceeds from the right to left to reach equilibrium

Question 14

Qc = Kc

Accepted Answer

the system is at equilibrium

Question 15

Qc < Kc

Accepted Answer

system proceeds from left to right to reach equilibrium

Question 16

Le Chatelier's Principles

Accepted Answer

if an external stress is applied to a system at equilibrium, the system adjusts in such a way that the stress is partially offset as the system reaches a new equilibrium position

Question 17

variable that can be controlled experimentally

Accepted Answer

concentration, pressure, volume, and temperature

Question 18

concentrations of gases are greatly affected by:

Accepted Answer

changes in pressure

Question 19

the greater the pressure the ______ the volume

Accepted Answer

smaller

Question 20

What is the only thing that can affect the equilibrium constant

Accepted Answer

temperature

Question 21

increasing the concentrations of products shifts the equilibrium to the

Accepted Answer

left

Question 22

decreasing concentration of products shifts the equilibrium to the

Accepted Answer

right

Question 23

increasing the concentration of reactants shifts the equilibrium to the

Accepted Answer

right

Question 24

decreasing the concentration of reactants shifts the equilibrium to the

Accepted Answer

left

Question 25

increasing pressure

Accepted Answer

shifts the equilibrium to side with the fewest moles of gas

Question 26

decreasing pressure

Accepted Answer

shifts the equilibrium to the side with the most moles of gas

Question 27

increasing volume

Accepted Answer

shifts the equilibrium to the side with the most moles of gas

Question 28

decreasing volume

Accepted Answer

shifts the equilibrium to the side with the fewest moles of gas

Question 29

temperature increases favor

Accepted Answer

endothermic reactions

Question 30

temperature decreases favor

Accepted Answer

exothermic reactions

Question 31

Adding a catalyst

Accepted Answer

does not alter the equilibrium constant, not does it shift the position of an equilibrium system.

Question 32

If a reaction can be expressed as the sum of two or more reactions, the equilibrium constant for the overall reaction is given by what?

Accepted Answer

equilibrium constants of the individual reactions.

Question 33

When the equation for a reversible reaction is written in the opposite direction, the equilibrium constant becomes what?

Accepted Answer

the reciprocal of the original equilibrium constant.

Question 34

The concentrations of the reacting species in the condensed phase are expressed in?

Accepted Answer

M

Question 35

the concentrations of the reacting species in the gaseous phase are expressed in?

Accepted Answer

M or atm

Question 36

Are the concentrations of pure solids and liquids expressed in the equilibrium constant expression?

Accepted Answer

No

Question 37

The equilibrium constant in what kind of quantity?

Accepted Answer

dimensionless

Question 38

Kc=

Accepted Answer

Kf/kr

Question 39

ICE

Accepted Answer

Initial, change, equilibrium

Question 40

increasing temp

Accepted Answer

k decreases in an exothermic reaction and K increases in an endothermic reaction

Question 41

decreasing temp

Accepted Answer

k increases in an exothermic reaction and K decreases in an endothermic reaction

Question 42

According to Le Chatelier's Principle adding a catalyst does what?

Accepted Answer

1. Doesn't change the K 2. doesn't shift the position of an equilibrium system 3. system will reach equilibrium sooner.

Question 43

List the four factors that can shift the position of equilibrium. Which is the only one that can alter the value of the equilibrium constant?

Accepted Answer

Concentration, temperature, pressure, volume. Temperature i

Question 44