Video Transcript
Which statement explains what is
meant by the equilibrium position being on the left? (A) The concentration of the
products is greater than that of the reactants. (B) The rate of the forward
reaction is greater than that of the backward reaction. (C) The concentration of the
reactants is greater than that of the products. (D) The rate of the backward
reaction is greater than that of the forward reaction.
Equilibrium position can be used to
describe a dynamic equilibrium. A dynamic equilibrium is an
equilibrium between forward and reverse reactions where both reactions occur at the
same nonzero rate. When dynamic equilibrium has been
established, the concentrations of the reactants and products remain constant. This is because as the reactants
are converted into products, the products are being converted back into reactants at
the same rate. However, just because the
concentrations remain constant during dynamic equilibrium does not mean that the
concentrations of the reactants and products have to be equal. The relative concentrations of the
reactants and products at equilibrium can be indicated using equilibrium
position.
Equilibrium position can be
calculated by dividing the concentration of the products by the concentration of the
reactants once dynamic equilibrium is established. When the equilibrium concentrations
of the reactants and products are equal, the equilibrium position will be one. When the equilibrium concentration
of the reactants is greater than the products, the equilibrium position will be less
than one. This equilibrium position is said
to lie to the left. When the equilibrium concentration
of the products is greater than the reactants, the equilibrium position will be
greater than one. This equilibrium position is said
to lie to the right.
The question asks what is meant by
the equilibrium position being on the left. We know that when the equilibrium
position lies to the left, the concentration of the reactants will be greater than
the concentration of the products. Therefore, the statement that
explains what is meant by the equilibrium position being on the left is answer
choice (C). The concentration of the reactants
is greater than that of the products.
