Question

If the equilibrium constant for a reaction is 0.00010, what does this tell us about the position of equilibrium for that reaction?

A. There are more reactants than products at equilibrium.
B. There are more products than reactants at equilibrium.
C. At equilibrium, the concentration of reactants is the same as that of the products.
D. The concentration of the product at equilibrium is 0.00010 M.

Answer 1

Answer: A. There are more reactants than products at equilibrium.

Explanation:

Equilibrium constant is defined as the ratio of concentration of products to the concentration of reactants each raised to the power their stoichiometric ratios. It is expressed as $K_{eq}$

For a general chemical reaction:

$aA+bB\rightarrow cC+dD$

The expression for $K_{eq}$ is written as:

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

There are 3 conditions:

When $K_{eq}>1$; the reaction is product favored.

When $K_{eq}<1$; the reaction is reactant favored.

When $K_{eq}=1$; the reaction is in equilibrium.

From the above expression, the equilirbium constant is directly dependent on product concentration. Thus, more is the concentration of product, more will be the equilibrium constant.

The values of $K_{eq}$ less than 1 , means the reactant are more than the products.