What is the purpose of finding log k?
$\log K$ relates to the thermodynamic changes in entropy and enthalpy of a reaction.
$$\Delta H - T \Delta S = \Delta G = \Delta G^\circ - RT \ln Q$$

At equilibrium $Q = K$ and:

$$\Delta G = 0 = \Delta G^\circ - RT \ln K \Longrightarrow  \Delta G^\circ = RT\ln K$$

$$\Delta G^\circ = \Delta H^\circ -T\Delta S^\circ = RT \ln K$$

and:

$$\ln K = \frac{\Delta H^\circ -T\Delta S^\circ}{RT} = \frac{\Delta H^\circ}{RT} - \frac{\Delta S^\circ}{R}$$