What is the solute and the solvent in fog?

Answer 1

Solute = H2O(g), solvent = air (mostly N2 and O2 gas)

Answer 2

Fog is an aerosol, a type of colloid where the continuous phase is gaseous and the dispersed phase can be either solid or liquid.

In the case of fog, the "solute" is water and the "solvent" is air.

Answer 3

The solvent may considered air and the solute is the fog (gaseous water).