what is the difference between a percent saturated solution of ammonium sulfate and a percent w/v solution of ammonium sulfate?

Answer 1

X% saturated means the solvent contains X% of the maximum possible (saturation) amount of solute at that temperature.

X% w/v sounds like a weight/volume ratio, but that would have to be in some units like grams ammonium sulfate per liter H2O, not %.