equilibrium - Kc and Kp

Question 1

equation for Kc

Answer 1

Kc = [products] / [reactants]

Question 2

what is homogenous equilibria

Answer 2

• species all have the same state

Question 3

what is heterogenous equilibria

Answer 3

• species with different states

- only include gases/aq in the Kc expression

Question 4

mole fraction equation

Answer 4

x(A) = number of moles of A / total moles in gas mixture

sum of MF = 1

Question 5

partial pressure equation

Answer 5

p(A) = x(A) x total pressure in system

Question 6

Kp expression

Answer 6

Kp = p(products) / p(reactants)

- only include gases

Question 7

magnitude of K relate to eq position

Answer 7

K = 1 : eq halfway between R + P
K = greater than 1 : towards P
K = less than 1 : towards R

Question 8

effect of temp on Kp

Answer 8

Exothermic:

• temp inc
• Kp decreases
• eq shifts to left

Endothermic

• temp inc
• Kp inc
• eq shifts to the right

Question 9

effect of conc + pressure on K

Answer 9

• no effect

Question 10

catalyst effect on k

Answer 10

• no effect
• catalysts affect rate of a reaction
• not the position of equilibrium
• speed up forward and reverse reaction by the same factor
• so equilibrium is reached quicker.