Solubility Rules

Question 1

What salts/bases are soluble in aqueous solutions without exception?

Answer 1

Salts/bases that are formed from the group 1A elements (alkali metals) and ammonium. Also, salts/bases with the following anionic constituents: nitrates (NO₃^-), nitrites (NO₂^-), acetates (CH₃COO^-), ClO_x^-, and iodates (IO₃^-) are freely soluble in water.

Question 2

Salts/Bases that formed with the anionic constituent chloride (Cl^-), bromide (Br^-), or iodide (I^-), are freely soluble in aqueous solutions besides a few notable exceptions. There are several metals (M = metal) where M_xCl_y, M_xBr_y, M_xI_y form insoluble compounds. List these cationic constiuents.

Answer 2

Cu⁺, Ag⁺, Au⁺, [Hg₂]⁺², and Pb⁺²

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Question 3

Salts that formed with the anionic constituent, sulfate (SO₄^-2), are freely soluble in aqueous solutions besides a few notable exceptions. There are several metals (M = metal) where M_x(SO₄)_y, form insoluble compounds. List these cationic constiuents.

Answer 3

Sulfates are generally freely soluble in aqeuos media, excluding barium, strontium, lead (II), calcium, silver, and mercury (I)

BaSO₄
SrSO₄
PbSO₄
CaSO₄
Ag₂SO₄
Hg₂SO₄

Question 4

Sulfides (such as FeS) are generally insoluble in aqueous solutions. However, there are some sulfides that are soluble, name these exceptions.

Answer 4

Sulfides that form with the group 1A elements (i.e. Na_{2, Li2S}S, K₂S…etc.) group 2A elements (CaS, MgS, SrS…etc.) and ammonium sulfide (NH₄)₂S will be soluble in aqueous solutions.

Question 5

Carbonates (CO₃^-2), phosphates (PO₄^-3), silicates (SiO₄^-4), sulfites (SO₃^-2), and chromates (CrO₄^-2 and Cr₂O₇^-2) are generally insoluble in aqueous solutions. However, there are some that are soluble, name these exceptions.

Answer 5

Carbonates (CO₃^-2), phosphates (PO₄^-3), silicates (SiO₄^-4), sulfites (SO₃^-2), and chromates (CrO₄^-2 and Cr₂O₇^-2) that are paired with the group 1A elements, Ba⁺², Sr⁺², and Ra⁺² are all soluble in aqueous solutions.

Question 6

What base is said to be soluble, but does not break into ions when in aqueous solutions?

Answer 6

Ammonium nitrate (NH₄NO₃)