Question

Which ionic compound is the most likely to dissolve in water?



PbCl2


AgCl


Hg2Cl2


NaCl

Answer 1

Here is what is soluble in water
Most nitrate (NO3-) salts are soluble!
Most salts of Na+, K+, and NH4 are soluble! Exceptions: AgCl, PbCl2, Hg2Cl2
Most chloride salts are soluble! ExCeptions: BaSO4, PbSO4, CaSO4
Most sulfate salts are soluble!
Most hydroxide salts are only slightly soluble!
These are soluble in NaOH, KOH
Most sulfide, carbonate, and phosphate salts are only slightly soluble!

Answer 2

You generally have to memorize those rules and I keep forgetting them; the rules for solubility.