Question

How is the value of the equilibrium constant useful?

Answer 1

The value of the equilibrium constant tells us the extent to which the reactants or products predominate in a system which is at equilibrium.

Consider a general case :

`aA+bBrightleftharpoonscC+dD`

The expression for the equilibrium constant in terms of concentration is:

`K_c=([C]^(c)[D]^(d))/([A]^(a)[B]^(b))`

You can see that if the position of equilibrium lies to the right then `[C]` and `[D]` will be large and [A] and [B] will be small giving a large value of `K_c`.

`K` only depends on temperature so this must always stated when quoting any values.