equilibrium chp 19

Question 1

what do the values of Kc mean

Answer 1

the larger the value, the further the position of equilibrium towards the products.

Question 2

How do you find the units for Kc

Answer 2

the units of Kc depend upon the number of concentration terms on the top and bottom of the equilibrium constant term

• substitute units into the expression for Kc
• cancel common units and show the final units on a single line

Question 3

what are the 2 main types of equilibria

Answer 3

Homogeneous and heterogeneous

Question 4

what is a homogeneous equilibrium

Answer 4

A homogeneous equilibrium contains equilibrium species that all have the same state or phase

Question 5

What is a heterogeneous equilibrium

Answer 5

A heterogeneous equilibrium contains species of different states

Question 6

What are the differences in hetero and homo geneous equilibriums Kc expressions

Answer 6

• Kc expressions for homogenous equilibria contain concentration of all species involved in the reaction
• Kc expressions for heterogenous expressions omit concentrations for solids and liquids, only contain concentrations for aqueous and gases species

Question 7

what is Kp

Answer 7

Kp is the equilibrium constant in terms of partial pressure

Question 8

what is meant by mole fraction

Answer 8

it’s proportion by volume to the total volume of gas in a gas mixture

Question 9

what is the formula for mole fraction

Answer 9

Question 10

what is meant by partial pressure
whats the formula

Answer 10

the contribution that a gas makes towards the total pressure

Question 11

whata the difference between the Kc and Kp expressions

Answer 11

concentrations in the Kp expression are replaced with partail pressures

Question 12

what units can be used for partial pressures

Answer 12

• pascals, kilopascals and atmosphere
• all can be used but when calculating make sure they are all the same unit

Question 13

what do different rate constants mean

Answer 13

• K=1, indicates an equilibrium halfway between the products and reactants
• k=100, indicates an equilibrium that is well towards the products
• k=0.001, indicates equilibrium well infavour of reactants

Question 14

what is the only thing factor that can change the value of K, rate constant

Answer 14

• the temperature is the only factor that can change the rate constant

Question 15

How will changes in temperature effect the rate constant K, if the forward reaction is exothermic

Answer 15

• the equilibrium constant will decrease with increasing temperature
• raising the temperature decrease the equilibrium yeild of products