Reversable Reactions And Equilibria Flashcards
(21 cards)
What is a reversible reaction
A reaction which it’s products can react to form a the original reactants
⇌
How can the direction of the reversible reaction be changed
Changing reaction conditions
Temperature
Pressure
Concentration
What is dynamic equilibrium
Rate of the forward reaction = rate of backwards reaction
Concentration of the reactants and products are constant even though it’s continuously reacting
What is a closed system
A system where nothing is added or removed
Reactants and products remain in the reaction vessel
Why is equilibrium only reached if the reaction takes place in a closed system
The closed system prevents reactants and products escaping
So they can react continuously
What is Haber process
An industrial process used to produce ammonia - making fertilisers
What are the source of hydrogen and nitrogen in Haber process
Nitrogen - extracted from the air
Hydrogen - from natural gas
Conditions for Haber process
pressure 200 atmospheres
temperature 450°C
iron catalyst.
Chemical equating for Haber process
N2+3H2 ⇌ 2NH3
Turbogenerator + hydrogen - ammonia
Effect of changing the temperature in reversible reaction if foward reaction is endothermic
Increasing temperature favours foward reaction
Equilibrium will shift towards the forward reaction
yield of the products will increase
The effect of changing the concentration
Concentration of products or reactants is changed
System not in equilibrium
Concentration will change until equilibrium is reached again
Concentration of reactants increased
Position of equilibrium shifts towards products(right)
So more product is produced until equilibrium is reached
If concentration of products increased
Position of equilibrium shifts towards the reactants(left)
More reactant is produced until equilibrium is reached again
Effects of changing pressure
In gaseous reaction
Pressure will favour the reaction that produces the least number of molecules
Shown by the sumbol equation for that reaction
Increase in pressure
Reaction produces Large volume of gas:
Decrease yield of reaction equilibrium shifts left
Reaction produces small volume of gas:
Increase yield of reaction equilibrium shifts right
Decrease in pressure
Reaction produces Large volume of gas:
Increase yield of reaction equilibrium shifts right
Reaction produces small volume of gas:
Decrease yield of reaction equilibrium shifts left
Effect of changing temperature
If temperature increases equilibrium moves in the direction of the endothermic reaction
Yield - amount of product from the forward reaction
Increase in temperature
Yield -product from the foward reaction
(Products)
Exothermic
Decrease yield of reaction equilibrium to the left
Endothermic - increased yield of reaction - equilibrium to the right
Decrease in temperature
Yield -product from the foward reaction
(Products)
Exothermic
Increase yield of reaction equilibrium to the right
Endothermic - decrease yield of reaction - equilibrium to the left
Is the forward reaction exothermic or endothermic
Endothermic
Is the reverse reaction exothermic or endothermic
Exothermic
