Acetone - Can it already be anhydrous when purchased?
As correctly pointed out by @MaxW, the technical acetone still contains water.  In addition, it is better to quantify "dryness", so by passing a mark you may draw the line of "dry enough" for the application you aim for; especially as Karl Fischer analysis may provide you a reproducible figure of merit about the water content.

Now, if you need dry acetone, stirr the acetone with potassium carbonate or calcium chloride and subsequently distill it off into a dry container.  In the instance of acetone, however, I refrain from molecular sieves because they catalyze aldol reactions.