Module 5 Chapter 19 Flashcards
What is homogeneous equilibria
When all the species are in the same phase/state
What is heterogeneous equilibria
When species are in a different phase/state
What are solids and liquids regarded as and how are they used in the Kc equation
They are effectively constant
So they are omitted from the equilibrium expression
What can you use to calculate the equilibrium concentration when given the initial concentration
An ICE table
What occurs under the same conditions for gases
Under the same conditions of temperature and pressure the sane volume of different gases contains the same number of moles of gas volume.
What is the mole fraction the same as
The proportion by volume to the total volume of gases in a gas mixture
What is the mol fraction formula
The number of moles of A/ The total number of moles of GAS in the mixture
What do the mol fractions sum to equal
1
What is KP
KP is another way to calculate the equilibrium constant using partial pressures instead of concentrations
Why is KP sometimes easier to use than KC
As you need concentrations for Kc and this can be difficult to find out for a gas
What is partial pressure
It is the contribution that each gas makes towards the total pressure
What is the pressure of a gas proportional to at a fixed volume and constant temperature
The number of moles due to pv = nrt
What does the magnitude of K indicate
The extent of a chemical equibilirum
What do the different values of K mean
k = 1 equilibrium is halfway
K < 1 towards the reactants
K > 1 towards the product
What does the K give
The exact position of equibrium
What will the reaction continue until
The concentration of the species gives K
What does temperature do to K
Temperature is the only condition that causes K to change its value
What happens if the forward reaction is exothermic and the temperature increases
The equilibrium constant decreases with increasing temperature
Decreasing the equilibrium yield of the product
What happens if the forward reaction is endothermic and the temperature increases
The equilibrium constant increases with temperature
Increasing the equilibrium yield of the products
How do changes in concentration and pressure affect K, however how can they still affect equilibrium position
The value of K is unaffected by changed in concentration and pressure
However Le chatelier says that the equilibrium position can be shifted by changes in concentration and pressure
And this shift is caused by the equilibrium constant not changing.
What must you talk about when describing how pressure and concentration changes the value of the equibilibrium constant
How the value of the denominator or numerator in the equilibrium constant expression has increased or decreased
