Relationship between K and Rate Constants
The equilibrium constant of an elementary reaction equals the ratio of its forward and reverse rate constants.
Formula / equation
K = k_forward / k_reverse
Unit
Various
In depth
At equilibrium the forward and reverse rates are equal, and equating the two rate expressions gives this relation directly. It explains why a catalyst cannot shift equilibrium: it raises both rate constants by the same factor, leaving their ratio untouched.
Examples in the real world
A forward rate constant of 0.20 with a reverse constant of 0.005 gives K = 40.