How far? Flashcards
What is mole fraction of A?
The number of moles of A divided by the total number of moles in the mixture
What is the mole fraction equation?
Mole fraction = number of moles of A / total number of moles in a gas mixture
What is partial pressure?
Mole fraction of A x total pressure P
What does the sum of all partial pressures of a gas equal?
The total pressure of the mixture
How do you calculate quantities at equilibrium?
What are the techniques and procedures used to determine quantities present at equilibrium?
- Titrations
- Use of colorimeter - measure the amount of light passing through a substance. If a dark substance is being produced less light will pass through and this shows that there is a higher concentration produced
What states do you discount in a Kc equation?
Solids and liquids because there concentrations are essentially constant
How do you calculate the Kp value of general equation aA + bB <=> cC ?
Kp = p[C]^c / p[A]^a p[B]^b
where p = the equilibrium partial pressure
What states does the Kp equation involve?
Gases only because only gases have partial pressure
What are acceptable units for partial pressure?
Pa, kPa and atm
If the forward reaction is exothermic, what does the equilibrium constant do with with increasing temperature?
Decreases - it also decreases the yield of the products
If the forward reaction is endothermic, what does the equilibrium constant do with increasing temperature?
Increases - the equilibrium yield of the products also increases
If the forward reaction is exothermic, what does the Kp value do with with increasing temperature?
Decrease - the equilibrium position shifts to the left
If the forward reaction is endothermic, what does the Kp value do with with increasing temperature?
Increase - the equilibrium position shifts to the right
What are the equilibrium constants unaffected by?
Changes in concentration or pressure and a catalyst
By le Chateliers principle it is known that the equilibrium position can be shifted by changes in pressure or concentration. This shift actually occurs from the equilibrium constant not changing
