Dynamic Equilibrium

Question 1

what is dynamic equilibrium?

Answer 1

• occurs in a closed system when the rate of the forward reaction is equal to the rate of the reverse reaction
• the concentrations of reactants and products don’t change

Question 2

what is Le Chatelier’ principle?

Answer 2

position of dynamic equilibrium shifts to minimise the effect of any change

Question 3

what is Le Chatelier’s principle applied to?

Answer 3

homogenous equilibrium

Question 4

what can affect the equilibrium position?

Answer 4

• temperature
• concentration
• pressure

Question 4

what is homogeneous equilibrium?

Answer 4

all reaction species are in the same state or phase

Question 5

what happens to equilibrium position if the temperature increases?

Answer 5

increase in temp = endothermic direction (+ve)
- to oppose increase in temp

Question 6

what happens to equilibrium position if the temperature decreases?

Answer 6

decrease in temp = exothermic direction(-ve)
- to oppose decrease in temp

Question 7

what happens to equilibrium position if the concentration of reactants increases?

Answer 7

• equilibrium position shifts right to oppose the increase in conc of reactants

Question 8

what happens to equilibrium position if the concentration of reactants decreases?

Answer 8

• equilibrium position shifts left to oppose the decrease in conc of reactants

Question 9

what happens to equilibrium position if the concentration of products increases?

Answer 9

• equilibrium position shifts left to oppose the increase in conc of products

Question 10

what happens to equilibrium position if the concentration of products decreases?

Answer 10

• equilibrium position shifts right to oppose the decrease in conc of products

Question 11

what does change in pressure affect?

Answer 11

gaseous molecules only

Question 12

what happens to equilibrium position if the pressure increases?

Answer 12

• pressure increases = favours side with least gas molecules

Question 13

what happens to equilibrium position if the pressure decreases?

Answer 13

• pressure decreases = favours side with more gas molecules

Question 14

what effect do catalysts have on equilibrium position?

Answer 14

• no effect on equilibrium position
• increase the rate of both the forward and reverse reaction in equilibrium by the same amount = unchanged equilibrium position

Question 15

why is a high pressure bad?

Answer 15

provides a safety risk

Question 16

why is a high temperature not good?

Answer 16

• expensive
• lots of energy is used

Question 17

why is a low temperature bad?

Answer 17

slow rate of reaction

Question 18

what effect does a catalyst have on equilibrium mixture?

Answer 18

• no effect
• catalysts only changes the rate of reaction