Reversible reactions and Dynamic equilibrium Flashcards
How do you get a dynamic equilibrium?
- rate of forward reaction = rate of backward reaction
- constant temperature and pressure
- a closed system - nothing gets in or out
Give two examples of reversible reactions.
NH4Cl NH4 + Cl
CoCl2 * 2H2O CoCl2 + 2H2O
hydrated: pink anhydrous: blue
What is the equilibrium percentages for the Habour Process, and the equation?
N2(g) + 3H2(g) 2NH3
___100%__________0%
____85%_________15%
What is Le Chatelier’s Principle?
Whenever a dynamic equilibrium is disturbed, it moves to oppose the disturbance (and equilibrium is restored)
Whatever factor you change, the reaction foes the opposite
How do Exothermic and Endothermic reaction affect the reaction and the symbols?
Exothermic - increases temperature (-/\H)
Endothermic - decreases temperature (+/\H)
What is the outline for effect of temperature on a reversible reaction?
- label the arrows
- if we increase/decrease the temperature in the system
- Le Chateliers states the system will increase/decrease temperature
- favours forward/backwards reaction
- exothermix/endothermic
- equilibrium shifts to the left/right
- more reactants/products made
What is the outline for effect of pressure on a reversible reaction?
- label the arrows
- if we increase/decrease the pressure in the system
- Le Chateliers states the system will increase/reduce temperature
- favours forward/backwards reaction
- equilibrium shifts to the left/right
- more/less moles of gas in reactants/products
- more reactants/products made
How do catalysts effect the equilibrium?
Don’t effect equilibrium position
speed up forward and backward reaction equally
What are the problems with high pressure and low temperature?
High pressure: too expensive to reinforce piping, energy costs
Low Temperature: reaction rate is too slow, high temperature is used (fast rate - remove products)
How do you calculate the Kc?
Kc = [products] / [reactants] [] = concentration
