Chemical Equilibria

Question 1

what does dynamic equilibrium mean?

Answer 1

where the forwards rate of an equation is equal to the backwards rate in a closed system where the concentration reams constant

Question 2

what is Le Chatelier’s principle?

Answer 2

equilibrium will shift to oppose the change on a system

Question 3

what are the 3 factors that affect the position of equilibrium?

Answer 3

• Concentration
• Pressure
• Temperature

Question 4

what effect does a catalyst have on the position of equilibrium?

Answer 4

• no effect
• the catalyst increases the rate of both forward and backwards reactions at the same time

Question 5

what is homogeneous equilibrium?

Answer 5

a system in which the reactants and products are in the same phase

Question 6

how do you calculate K꜀ (equilibrium constant)

Answer 6

K꜀ = [products]ᵃ / [reactants]ᵇ
a and b = the number of moles of the species which appear in the balanced equation for equilibrium

Question 7

What factor is K꜀ affected by

Answer 7

Temperature

Question 8

what are the optimum conditions for the Haber process and why

Answer 8

650-720K - synthesis of ammonia is exothermic therefore there is a higher yield at a lower temp, however low temp = slow rate of reaction therefore compromise temp used

2.0 x 10⁴ kPa - synthesis of ammonia favours higher pressure however it is expensive to generate and requires complex equipment to withstand therefore compromise pressure used

Iron catalyst - reduces time taken to reach equilibrium