Ion solubility in water

Question 1

What are the ionic compounds that are always soluble in water ?

Answer 1

1. Alkaline metals (first row) Na+, K+, Li+, Rb+, Cs +
2. Polyatomic atoms
   * NH4+
   * C2H3O-
   * ClO3-
   * Cl04-

Question 2

Which ionic compounds are usually soluble in water

Answer 2

1. On their own: Cl-, Br-, I-
   Except when these are paired with
   Ag+, Pb+ and Hg2 2+

meaning anytime these are in an aqueous solution with the above they will most likely precipitate

2. Polyatomic atom
   Sulfate (SO4 -2) - except when it is paired with Ca+, Ba+ Sr+, Pb +
   Fluorides (F-)- except when paired with Ca+, Ba+, Sr+, Pb+, Mg -2

Question 3

Which ionic molecule or compound are usually never soluble?

Answer 3

-O2 or OH- ( oxide or hydrogen)

Except when paired with Ca2+, Ba 2+, Sr 2

Question 4

Which ionic compound are never soluble?

Answer 4

CO3-2 , PO4 -3, S2-, SO3 -2, CrO4 -2,
C2O4 -2
Execpt metals and Amonium