3.2.3 Equilibrium

Question 1

dynamic equilibrium

Answer 1

when the forward and backwards reactions occur at equal rates
concentrations of reactants and products stay constant and the reaction is continuous

Question 2

what is le chatlier’s principle

Answer 2

if an external condition is changed equilibrium will shift to oppose the change

Question 3

what is the effect of temperature on equilibrium

Answer 3

• increase in temperature, equilibrium shifts to oppose so to the endothermic direction
• decrease in temperature, equilibrium will shift to oppose so to the exothermic direction

Question 4

what is the effect of pressure on equilibrium

Answer 4

pressure only affects equilibrium in gases

• increase in pressure, equilibrium shifts to oppose and shift towards the side with less moles of gas
• decrease in pressure, equilibrium shifts to oppose and shift towards the side with more moles of gas

Question 5

what is the effect of concentration on equilibrium

Answer 5

increase in concentration causes equilibrium to shift to oppose this

Question 6

what is the effect of catalysts on equilibrium

Answer 6

no effect

Question 7

give the equation for the hater process

Answer 7

N2 + 3H2 2NH3

Question 8

why can industrial processes not exist in true equilibrium

Answer 8

because they are not in a closed system

Question 9

give the equation for the equilibrium constant Kc

Answer 9

aA+bBcC+dD
Kc=[C]^c[D]^d/[A]^a[B]^b
liquids and solids are not included as they remain constant

Question 10

effect on equilibrium if Kc=1

Answer 10

equilibrium is halfway between reactants and products

Question 11

effect on equilibrium if Kc>1

Answer 11

equilibrium favours the products

Question 12

effect on equilibrium if Kc<1

Answer 12

equilibrium favours the reactants

Question 13

what conditions have no effect on Kc

Answer 13

concentration, pressure and catalysts

Question 14

what effect does temperature have on Kc

Answer 14

• if temperature increases Kc increases if delta H is positive and decreases if delta H is negative
• if temperature decreases Kc decreases if delta H is positive and increases if delta H is negative