Chapter 19 - Kc and Kp

Question 1

how to calculate homogeneous Kc

Answer 1

conc products/conc reactants

Question 2

how to calculate heterogeneous Kc

Answer 2

remove any (s) or (l) form equation as they have a constant concentration. Only use (aq) and (g)

Question 3

homogeneous Kp

Answer 3

p(products)/p(reactants)

Question 4

heterogenous Kp

Answer 4

only use (g) - only gases have pressure

Question 5

mole fraction

Answer 5

moles of substance/ total moles of gas

Question 6

partial pressure

Answer 6

total pressure x mole fraction

(Pa = XaP)

Question 7

what is the total pressure of a reaction

Answer 7

the sum of the partial pressures

Question 8

Kc/Kp of <1

Answer 8

equilibrium shifts left

Question 9

Kc/Kp of = 1

Answer 9

equilibrium halfway

Question 10

Kc/Kp of >1

Answer 10

equilibrium shifts right

Question 11

how does temp affect Kc/Kp if forward reaction is exothermic

Answer 11

• increasing temp decreases constant decreasing equilibrium yield of product

Question 12

how does temp affect Kc/Kp if forward reaction is endothermic

Answer 12

• increasing temp increases constant increasing equilibrium yield of product

Question 13

why does changing conc have no effect on Kc/Kp

Answer 13

if a concentration is changed the reaction is not at equilibrium so you cant find the equilibrium constant

Question 14

why does changing pressure have no effect on Kc/Kp

Answer 14

the changes in pressure occur at the same rate and so the cancel out and have no overall effect

Question 15

what do changing conc and pressure have an effect on

Answer 15

position of equilibrium, not the constants