If an anhydrous Cupric Perchlorate weighs 262.447g/mol initially and weighs 370.540 g/mol after sitting on the bench to absorb water from the air, the number of water molecules absorbed would be 6 moles.
First, let us calculate the amount of water gained during the course of staying on the bench:
Water gained = weight after gaining water - initial weight
= 370.540 - 262.447
= 108.093g/mole
The total amount of water gained per mol is 108.093. Each water molecule weighs 18.015 g/mole. Thus, the total number of water molecules that will sum up to 108.093 would be:
108.093/18.015 = 6 moles
In other words, the number of water molecules absorbed by the Cupric Perchlorate is 6 moles.
More on calculating water of hydration can be found here: https://brainly.com/question/919417