concentrations, or .
What’s the significance of that ratio? Suppose that in a particular reaction,
almost all of the reactants are converted into products and that products do not
reform reactants to any great extent. How would the Keq of the reaction reflect
such behavior? Well, product concentrations would be much greater than
reactant concentrations at equilibrium. As a result Keq, which is roughly a ratio
of product concentrations to reactant concentrations, will be a relatively large
number (greater than 100).
If, instead, we have a reaction in which reactants form relatively little product,
then Keq will be relatively small (smaller than , or 1 × 10−2). If product
and reactant concentrations at equilibrium are somewhat close, then Keq will be
close to 1 (not particularly large or small). So the value of the equilibrium
constant Keq of the reaction can give us a good idea about the extent to which
reactants form products.
Some Great Keq Facts
Solvents (usually H 2 O) are not included in the equilibrium expression.Each concentration is taken to the power of its coefficient in the balanced
equation.Equilibrium Facts