WEBSolubility Guidelines for Aqueous Solutions. Strong Acids and Bases. Acids: HCl, HBr, HI, HNO3, H2SO4 (first H+ only), HClO3, HClO4 Bases: Group 1 hydroxides (NaOH, KOH, etc.), Ca(OH)2*, Ba(OH)2*, Sr(OH)2* (*considered strong at concentrations below 0.10 M) Ka and Kb Values for Some Common Weak Acids …