Equilibrium

Question 1

What is dynamic equilibrium?

Answer 1

• When a reversible reaction is left in a sealed container, and the forwards and backwards reactions ‘balance out’
  -the products and reactants from this point are in ‘dynamic equilibrium’

Question 2

analogies to remember concept of dynamic equilibrium

Answer 2

• Walking up down escalator as the same speed-not moving
• people leaving front of queue as fast as people join at back- stays same length

Question 3

What is equilibrium position?

Answer 3

• the resulting balance of products and reactants in an equilibrium mixture

Question 4

What is meant by equilibrium being ‘on the left’

Answer 4

• there are more reactants than products in the mixture

Question 5

what is meant by equilibrium being ‘on the right’

Answer 5

• more products than reactants in the mixture

Question 6

example of dynamic equilibrium to remember

Answer 6

decomposition of N2O4

Question 7

Equation for decomposition of N2O4

Answer 7

N204 (g) <=> 2NO2 (g)

Question 8

What colour is NO2 gas

Answer 8

Brown

Question 9

In decomposition of N2O4, very dark brown mixture means…

Answer 9

equilibrium is (quite far) to the right

Question 10

In decomposition of N2O4, very light yellow/almost colourless mixture means…

Answer 10

equilibrium is (quite far) to the left

Question 11

Factors effecting direction of equilibrium shift (right or left)

Answer 11

• amount of reactants or products
• gas pressure
• temperature

Question 12

What is Le Chatelier’s principle?

Answer 12

• ‘The equilibrium shifts to counteract any change imposed on it’

Question 13

What is the shift direction when a substance is added?

Answer 13

In whichever direction uses it up

Question 14

What is shift direction when a substance is removed?

Answer 14

In whichever direction creates it (so that more of it gets created)

Question 15

What is shift direction when gas pressure is increased?

Answer 15

To whichever side has fewer moles of gas

Question 16

What is shift direction when gas pressure is decreased?

Answer 16

To whichever side has more moles of gas

Question 17

What is shift direction when temp is increased?

Answer 17

To whichever direction is endothermic

Question 18

What is shift direction when temp is decreased?

Answer 18

To whichever direction is exothermic