equilibrium

Question 1

characteristics of dynamic equilibrium

Answer 1

• the rate of the forward reaction is equal to the rate of the reverse reaction
• the systems closed
• concentration of reactants and products doesn’t change

Question 2

when is dynamic equilibrium reached on a graph

Answer 2

when the lines meet

Question 3

when there is more reactants than products which way does equilibrium lie

Answer 3

left

Question 4

when there is more products than reactants which way does equilibrium lie

Answer 4

right

Question 5

why does it lie to the right

Answer 5

higher yield of product

Question 6

what’s le chateliers principle state

Answer 6

when a system in a dynamic equilibrium is subjected to change, equilibrium position shifts to minimise the change

Question 7

effect of concentration of dynamic equilibrium

Answer 7

reactants conc increase
shifts right
product conc increase
shifts left
reactant conc decreases
shift left
product conc decreases
shift right

Question 8

why?

Answer 8

equilibrium shifts … to minimise an increase in … concentration

Question 9

effect of pressure on dynamic equilibrium

Answer 9

gas moles of reactants increase
shifts right
gas moles of products increases
shift left
gas moles of reactants decreases
shifts left
gas moles of products decreases
shifts right

Question 10

why

Answer 10

equilibrium shift .. to minimise pressure increase because there’s more moles of gas on …

Question 11

effect of temperature on dynamic equilibrium

Answer 11

exothermic forward reaction ( temperature is increasing )
shifts left
endothermic forward reaction ( temperatures decreasing )
shift left

Question 12

why

Answer 12

if temperatures increasing equilibrium shifts to the left to minimise an increase in temperature by absorbing heat
if temperatures decreasing equilibrium shifts to the right to minimise a decrease in temperature by releasing heat
because the forward reaction is …

Question 14

effect of catalyst on dynamic equilibrium

Answer 14

it doesn’t effect the position of the equilibrium

Question 15

in industrial processes why does equilibrium need to shift right

Answer 15

high yield
fast rate

Question 16

theoretical temperature for high yield and compromised conditions?

Answer 16

low temperature, so equilibrium shifts right as it’s exothermic
compromised conditions : rate to slow, not enough activation energy

Question 17

theoretical pressure for high yield?

Answer 17

high pressure so equilibrium shifts right as less moles on right side
compromised condition: dangerous, expensive

Question 18

what’s Kc measure

Answer 18

quantitative measure of ratio of product to reactant to determine equilibrium

Question 19

Kc equation

Answer 19

Kc = (C)c + (D)d / (A)a + (B)b
or products / reactants

Question 20

what are the typical units

Answer 20

mol dm-3

Question 21

how do you work out units

Answer 21

place them as a fraction then cancel out
big number in equation - lowercase letter
if it’s a diatonic molecule, capital letter is squared

Question 22

if only the denominator remains what will units be

Answer 22

dm3 mol-1

Question 23

Kc = 1

Answer 23

position is halfway

Question 24

Kc > 1

Answer 24

position lies right

Question 25

Kc < 1

Answer 25

position lies left

Question 26

if a change in temp causes equilibrium to shift right, kc..

Answer 26

increases

Question 27

if a change in temp causes equilibrium to shift left, kc..

Answer 27

decreases