Cambridge International A Levels Chemistry (Chapter 8-Equilibrium)

Cambridge International
AS Level
Chapter 8: Equilibrium
https://www.youtube.com/watc
h?v=kGSPAkOgN3U



CIE AS Chemistry

, 7.1 CONCEPTS OF DYNAMIC EQUILIBRIUM
 Reality: only few reactions proceed in
one direction
 A reaction that goes to completion, and
results in only products (and excess
reactants) remaining is non–reversible
 These reactions are often highly
exothermic
 Example: combustion process



CIE AS Chemistry

,7.1 CONCEPTS OF DYNAMIC EQUILIBRIUM
 Most reactions are reversible
 These reactions will have a forward
reaction and a backward reaction
 Eg: 2NO2(g) ↔ N2O4(g)
 Forward reaction: 2NO2(g) → N2O4(g)
 Backward reaction: N2O4(g) → 2NO2(g)




CIE AS Chemistry

, 7.1 CONCEPTS OF DYNAMIC EQUILIBRIUM
 At equilibrium, the system has the
mixture of reactants and product and
concentration of both product and
reactant remain constant but not
necessarily to be equal
 At this point the macroscopic properties
of the substances are constant while the
microscopic level of the individual
substances continue moving between
phases
 (see Hodder’s p.173 for more detailed
explanation)
CIE AS Chemistry