In the basement of our apartment building, we have 10+ bags of calcium chloride stacked up; they are used to melt sidewalk ice in the winter. I’ve noticed that there is a constant wet spot on the cement under and around those bags and I’m thinking that the hydrophilic quality of the salt may be drawing humidity from the basement. The bags aren’t totally sealed, I’d guess, and probably have some degree of powdered residue of salt on them. Is my guess as to the source of the wet spot likely correct?
Yes. Calcium chloride will absorb so much water from the air that it will dissolve. This property is called deliquescence. If it just absorbs water but not so much as to dissolve it is hygroscopic.
yes, its the salt being hydrophylic. Water molecules stick to it and the end result is the puddle on the floor. and then the salty water won’t evaporate - the salt slows down evaporation too. The puddle of water on the floor may remain whereas pure water the same size would evaporate away quickly…