CC12 Flashcards
What are reversible reactions?
A chemical reaction where the products react to reform the reactants.
What symbol is used for reversible reactions?
The ‘⇌’ sign is used to show that both forward and backward reactions occur at the same time.
What is dynamic equilibrium?
When the forward and backward reactions in reversible reactions are occurring at the same rate.
What type of systems does dynamic equilibrium occur in?
Dynamic equilibrium only occurs in closed systems, where there are no loss of reactants or products.
Why can dynamic equilibrium only occur in closed systems?
As in open systems, gases could escape and so equilibrium would not be achieve while in closed systems, there are no loss of reactants or products.
What is the equilibrium position?
The percentages of products and reactants at equilibrium.
What are the conditions in the Haber process?
A temperature of 450c°, a pressure of 200 atmospheres and the use of an iron catalyst.
How are reaction conditions chosen in the Haber process?
In the Haber process, the reaction conditions are chosen to favour the forward reaction and make a large amount of product as cheaply as possible.
What can alter the equilibrium position?
Changes in temperature can alter the equilibrium position.
Where does equilibrium position shift when increasing concentration?
Sends the equilibrium towards the opposite side.
Where does equilibrium position shift when decreasing concentration?
Sends the equilibrium towards the same side
Where does equilibrium position shift when increasing pressure?
Favours the side with fewer moles (the big number at the front of an element)
Where does equilibrium position shift when decreasing pressure?
Favours the side with more moles (the big number at the front of an element)
Where does equilibrium position shift when increasing temperature?
In an exothermic reaction = goes in the backwards direction (left)
In an endothermic reaction = goes in forward direction (right)
Where does equilibrium position shift when decreasing temperature?
In an exothermic reaction = goes in forward direction (right)
In an endothermic reaction = goes in backward direction (left)
