A reaction has a forward rate constant of 2.3 * 106 s-1 and an equilibrium constant of 4.0 * 108. what is the rate constant for the reverse reaction?

Answer is: 5,75·10⁻¹.

Kf = 2,3·10⁶ 1/s.

K = 4,0·10⁸ 1/s.

Kr = ?

Kf - forward rate constant.

K - equilibrium constant.

Kr - reverse rate constant.

Since both Kf and Kr are constants at a given temperature, their ratio is also a constant that is equal to the equilibrium constant K.

K = Kf/Kr.

Kr = Kf/K = 2,3·10⁶ 1/s : 4,0·10⁸ 1/s = 5,75·10⁻¹.