Most of the airlaw revolved around flight and duty type questions, M/Rs commercial/rpt operations dropping of articles, carriage of animals instruments required etc
I took a week to study for CPL airlaw and less for ATPL airlaw (most of the study time for ATPL airlaw was tagging my documents). You should have a good grounding of the regs before you attempt it and be able to quickly reference something.
As J3 alluded to, the devil is in the detail with the questions. Read them very carefully especially with flight and duty as a different word here or there can mean a whole different ball game.