Chemical Equilibrium Notes

Chemical Equilibrium

Dynamic Equilibrium

  • Dynamic equilibrium is reached when the rate of the forward reaction equals the rate of the reverse reaction.

  • A reversible reaction is a chemical reaction where the reverse reaction significantly contributes to the overall reaction.

Equilibrium Position

  • Equilibrium can lie to the left, in the middle, or to the right, indicating the relative amounts of reactants and products at equilibrium.

Why Reactions Reach Equilibrium

  • Concentrations affect reaction rates: higher concentrations generally lead to faster reaction

  • As the forward reaction proceeds, product concentration increases, accelerating the reverse

Equilibrium Constant, Keq

  • The equilibrium constant indicates the equilibrium position of a reaction at a given temperature, applying to one-step reactions.

  • For a multi-step reaction:

aA+bB⇌cC+dDaA + bB \rightleftharpoons cC + dD

  • The equilibrium constant expression is:

Keq=[C]c[D]d[A]a[B]bK_{eq} = \frac{{[C]^c [D]^d}}{{[A]^a [B]^b}}

Understanding Keq Values

  • Reaction favors the products.

  • Reaction favors the reactants.

Le Châtelier’s Principle

  • If is added to a system at equilibrium in the reaction $$, the reaction will shift to consume