7 CHEMICAL EQUILIBRIA

Question 1

reversible reaction

Answer 1

a reaction that can occur in both directions

Question 2

dynamic equilibrium

Answer 2

a reversible reaction in which the forward and backward reactions are both taking place at the same rate, resulting in no overall changes in concentration

Question 3

Le Chatelier’s Principle

Answer 3

if the conditions of a system at equilibrium are changed, the position of equilibrium shifts so as to reduce that change.

Question 4

conditions for Haber process

Answer 4

450 ℃
250atm
finely divided iron catalyst

Question 5

Haber process unexpected conditions reasons

Answer 5

too low temperature > reaction too slow > too costly

too high pressure > need specialised equipment to withstand high pressure > costly

Question 6

deduce p.o.e & K from the sign of △G

△G < 0

Answer 6

spontaneous, p.o.e lies to the right. K>1

Question 7

reaction quotient Qc
if Qc> Kc, poe is:
Qc=Kc:

Answer 7

left

reaction is at equilibrium

Question 8

effect of conc on poe

Answer 8

as con/T↑, poe shifts_to_(consume/produce) by favouring__ reaction
state △in conc of all R&P

Question 9

effect of T on poe

Answer 9

as T↑, poe shifts_to_(consume/produce additional heat) by favouring__ reaction.
state △in conc of all R&P

Question 10

effect of P on poe

Answer 10

as V of container↓, P↑

poe shifts to__to ↓P(counteract △) by favouring the production of__(fewer) moles of gases

Question 11

effect of catalyst on poe

Answer 11

(1) lowers Ea of both forward and backward reaction by the same extent, (2) so both rates↑ by the same extent
(3) ↓time to reach equilibrium (4) but poe is not affected

Question 12

factors affecting rate constant k

Answer 12

k ↑ as T↑ or with presence of catalyst