3.8 Equilibrium constant

Question 1

Dynamic equilibrium?

Answer 1

Reversible reaction where the forward and backward reactions are equal, so the quantities of each substance stays the same.

Question 2

Le Chatelier’s principle?

Answer 2

states that if a system is at dynamic equilibrium, experiences a change in its conditions, the equilibrium will shift to minimise the change.

Question 3

Kc?

Answer 3

equilibria constant for concentration and is used for reactions that n solutions are aqeuous

Question 4

Kp?

Answer 4

equilibria constant of partial pressure and only involves gases

H2CO3 (aq) ——- 3H+ + CO32- (aq)

Kc - (H+) 2 ( CO32-)
/////////////////////
(H2CO3) 1

Question 5

Kc?

Answer 5

products / reactants

Question 6

Kp?

Answer 6

PNH32-
////////////
PN2XPH-3

Question 7

Interpreting equilibrium constants?

Answer 7

a perfect equilibrium has equal quantities of reactants + products
Kc = 1
if Kc = less than 1
this usually occurs when delta G is positive + reaction will not spontaneously occur
If Kc = greater than 1, the mixture is mainly products
Delta G = negative
so reaction will occur spontaneously
Equilibrium data indicates the relative stability of reactants and products but gives no indication as to how the reaction occurs,

Question 8

Reaction rate data?

Answer 8

the changes that occur between reactants and a transitional state that enable a deduction of what is happening during the reaction.
Reaction rate data describes what bonds are broken + made, illustrating it in a reaction mechanism.

Question 9

Industrial considerations?

Answer 9

kinetic, energetic + equilibrium data must be considered for any industrial process

Question 10

aim?

Answer 10

maximum product
produces quickly as possible
maximum efficiency, lowest cost

Question 11

Equilibrium yield?

Answer 11

can be altered using a change in concentration, pressure or temp
working out equilibrium constants identified which concentration, temp + pressure gives the highest yield.

Question 12

Kinetic energy?

Answer 12

rate can be maximised by increasing the temp, increases the pressure or adding a catalyst

Question 13

Energetic?

Answer 13

this identifies how much energy must be put into a system for reaction to occur
most processes are exothermic, so energy is given out in 1 reaction could be used for another

Question 14

Temp?

Answer 14

the only factor that affects equilibrium constants
if you change the temp

Question 15

exothermic reactions?

Answer 15

increasing temp
decreasing Kc and Kp

Question 16

endothermic reactions?

Answer 16

increasing temp
increases Kc and Kp