K=kforward/kreverse

[Norman Dis4C]

Can someone derive this equation for me? Why does K=kforward/kreverse?

[Jared Khoo 1G]

For hypothetical equation, A + B <-> C + D, K = [C][D]/[A][B]. We know that the rate of the forward reaction is k [A][B], and the rate of the reverse is k'[C][D]. At equilibrium (so we can use K), the forward rate is equal to the reverse rate. So, k [A][B] = k'[C][D]. If you divide [A][B] from both sides and k' from both sides, you get k/k' = [C][D]/[A][B], which is equal to K the equilibrium constant.