# If equilibrium constant is equal to 1, what does that mean?

Jan 10, 2015

Let's take a generic chemical equilibrium to try and determine what an equilibrium constant equal to 1 would mean. So,

$a A + b B r i g h t \le f t h a r p \infty n s c C + \mathrm{dD}$

The equilibrium constant for this reaction can be written as

K_(eq) = ([C]^(c) * [D]^(d))/([A]^(a) * [B]^(b)

Since the expression of the equilibrium constant depends on the equilibrium concentrations of both the reactans, and the products, we can determine that ${K}_{e q} \text{=1}$ would imply

${\left[A\right]}^{a} \cdot {\left[B\right]}^{b} = {\left[C\right]}^{c} \cdot {\left[D\right]}^{d}$

What this means is that the reactions favors neither products, nor reactants, and that the equilibrium will be reached as an intermediate mixture , i. e. the concentrations of the products and of the reactans will be the same.

By comparison, the higher the equilibrium constant is above 1, the greater the concentrations of the products relative to the reactans. The smaller this value is, as a fraction between 0 and 1, the greater the concentrations of the reactans relative to the products.