Solubility rules compounds containing group 1 alkali metals or ammonium (nh4+) are soluble. nitrates (no3−), chlorates (clo3−), perchlorates (clo4−), and acetates (c2h3o2−) are soluble. chlorides (cl−), bromides (br−), and iodides (i−) are soluble, except for compounds containing silver (ag+), mercury(i) (hg22+), and lead (pb2+). sulfates (so42−) are soluble, except for compounds containing calcium (ca2+), strontium (sr2+), barium (ba2+), and lead (pb2+). hydroxides (oh−), carbonates (co32−), and phosphates (po43−) are insoluble, except for compounds containing group 1 alkali metals and ammonium (nh4+). sulfides (s2−) are insoluble, except for compounds containing group 1 alkali metals, ammonium (nh4+), magnesium (mg2+), calcium (ca2+), strontium (sr2+), and barium (ba2+).