It reacts with other chemicaps a lot faster because there are more particles readily available at one point in time for reactions to occur
increase the surface area of a solid means to increase the area of solid
You increase the surface area
It will increase it, as more of the outer surface of the solid is incontact with the liquid that it is dissolving in. :)
There is no such thing as "surface area" of "solubility" since the latter refers to the maximum concentration in the solution of a solid (or liquid) in a liquid. "Surface area", as applied to such a phenomenon is meaningless. However, by *increasing* the surface area of, say, a salt, by grinding it, will increase its solubility. Maybe *that* is what the questioner meant.
It really depends on what solid you refer to. Basically, the surface area is basically taking a shape's net and finding the area of that.