In the equation $log\ S = log\ C + Z\ log\ A$,what does $C$ represent?

Which complex is most stable?
Where $k_d = \text{Dissociation constant}$

Phosgene is formed slowly from which one of the following on exposure to air and sunlight?

If the angle between the circles $x^2+y^2-2x-4y+c=0$ and $x^2+y^2-4x-2y+4=0$ is $60^{\circ}$,then $c$ is equal to

$A$ meter bridge is set up as shown to determine end corrections at $A$ and $B$. When a resistance of $15 \ \Omega$ is used in the left gap and $20 \ \Omega$ in the right gap,the null point is obtained at a distance of $42 \ cm$ from $A$. When these resistances are interchanged,the null point is obtained at a distance of $57 \ cm$ from $A$. The values of the end corrections are:

The reagent used in the Wolff-Kishner reduction is