What exactly you mean by a mixture of C1 to C10 hydrocarbons with water? The only way you'll get any of these materials to "mix" with water is to add a surfactant to stabilize an emulsion.
C1 through about C4 are gases at room temperature. They are sparingly soluble in water and come out of solution as soon as the pressure is let down, concentrating in the air space above the water. Surfactants aren't going to stop that from happening.
C5-C10 are liquids at room temperature, are all sparingly soluble in water (perhaps a few hundred ppm at most), and are all less dense than water, and so tend to form a film or sheen to a separate layer on top of water when allowed to contact with air- unless they are thoroughly emulsified.
In any case- dissolved gas, emulsified liquid or free product, you're dealing with pure component vapour pressures to determine what matters, i.e. the air/fuel mixture concentration in the headspace. It's as if the fuel and the water were in separate containers inside a common air space. Even in an emulsion there is no true solvation- you just have stabilized droplets of free product liquid hydrocarbon with its surface made "friendly" to the water by the surfactant. You get zero benefit from the presence of water, i.e. no vapour pressure suppression to reduce the concentration of flammables, other than by the presence of water vapour as an inert.
