7. Chem Equilibra

Question 1

define reversible rxn

Answer 1

rxn that can proceed in both forward and reverse directions.
rxn mixture contains qtys of all rxn species in the system

(reversible arrow)
might be cuz small Ea or Ea(forward) = Ea(backwards)

Question 2

define dynamic equilibrium
(condition: constant temp)

Answer 2

occurs in a CLOSED & reversible system, whr the rates of the forward and reverse rxns are the same. No net change in the conc of the rxn species

Question 3

how does Kc and Kp look like?

Answer 3

. kf [Y]ᶜ [Z]ᵈ
Kc = —– = —————–
kb [W]ᵃ [X]ᵇ

where abcd is stiochiometric coeff, and WX is reactants and YZ is products

same as Kp but instead of [Y] its pᵧᶜ

• kf and kb is rate constant of forward and backward rxn

Question 4

degree of dissociation eqn

Answer 4

total init amt of reactant

Question 5

rls btw Δ G and K
(its not exclusive btw oops)

Answer 5

∆G = -RT lnK
units: J mol⁻¹

Question 6

define Le Chatelier’s Principle

Answer 6

when stress is applies to system at equilibrium, POE would shift to minimise the stress

Question 7

Haber conditions

Answer 7

500⁰C
250 atm
finely divided iron

Question 8

pros and cons abt low temp

Answer 8

(+)forward exo favoured to prod more heat, POE shift right
(-) slow rate (solve w catalyst)

Question 9

pros and cons abt high pressure

Answer 9

(+) forward exn favoured to reduce pressure by prod less gaseous p
(-) high COP (maintenance, strong ex equipment)