In a closed system, when do reversible reactions attain a state of dynamic equilibrium
In a closed system, reversible reactions attain a state of dynamic equilibrium when the rates of of forward and reverse reactions are equal.
What is rarely equal at equilibrium
At equilibrium the concentration of reactants and products remain constant but are rarely equal
How do chemists maximise profit
To maximise profits, chemists employ strategies to move the position of equilibrium in favour of the product
What is the explanation of concentration (A+D)
A + B reversible C + D
- addition of A (one reactant) or subtraction of D (one product) favours the forward reaction and shifts the equilibrium to the right
- as the equilibrium has to remove additional (A) so forward reaction uses up more A
What is the explanation of concentration (C+A)
A + B reversible C + D
- addition of C (one product) or subtraction of A (one reactant) favours the reverse reaction and shifts the equilibrium to the left
- this is because the equilibrium is trying to regain its balance by pushing backward reaction to the left therefore producing more reactants
- Taking away A would have same affect as C + D would have to react to produce more A
Summary of effect of concentration on equilibrium
Concentration. Effect on equilibrium position
Addition of reactant or removal product Equilibrium shifts to the right
Addition of product or removal of reactant Equilibrium shifts to the left
What happens if the forward reaction is favoured
If the forward reaction is favoured we say the equilibrium has moved to the right
What happens if the reverse reaction is favoured
If the reverse reaction is favoured we say the equilibrium has moved to the left
Effect of changing temperature on an endothermic reaction
A + B reversible C + D
- increasing the temperature of A + B will shift equilibrium to the right the forward reaction takes in energy so it moves to the right
- decreasing the temperature of C + D will shift equilibrium to the left the reverse reaction gives out energy so equilibrium shifts to the left
Which reactions will equilibrium favour when temperature is changed
If the temperature is increased the equilibrium will favour the froward endothermic reaction. The equilibrium moves to the right
If the temperature is decreased the equilibrium will favour the reverse exothermic reaction. The equilibrium moves to the left
Temperature summary
Temperature Effect on equilibrium position
Increase Shifts in direction of the endothermic reaction
Decrease Shifts in direction of exothermic reaction
What is the effect of catalyst on equilibrium
The use of a catalyst does not change the equilibrium position it only enables the position of equilibrium to be reached more quickly
What is the effect of increasing pressure on equilibrium
- increasing the pressure will cause the equilibrium to move to the side with fewer particles to reduce the number of particles
- decreasing the pressure will cause the equilibrium to move to the side with more particles to increase the number of particles
What do hydrogen and hydroxide ions do to eachother
Hydrogen and hydroxide ions remove each other
When asked the addition of which of the following substances will affect equilibrium
Write out ionic formula of all options
-
1a) - Periodicity27
-
1b)i) - Structure and bonding52
-
1b)ii) - Structure and bonding41
-
1c) - Oxidising And Reducing Agents31
-
2a) - Systemtaic Carbon Chemistry21
-
2b) - Alcohols18
-
2c) - Carboxylic Acids15
-
2d) - Esters Fats And Oils43
-
2e) - Soaps Detergents And Emulsions27
-
2f) - Proteins15
-
2g) - Oxidation of Food21
-
2h) Fragrances12
-
2i) - Skin Care13
-
3a) - Getting The Most From Reactants18
-
3b)i) - Collision Theory13
-
3b)ii) - Reaction Pathways14
-
3b)iii) - Kinetic Energy Dustribution8
-
3c) - Chemical Energy19
-
3d) - Equilibria15
-
3e)- Volumetric Analysis9
-
Experimental Precedures19
