Question

According to the solubility rules given in Topic7b; predict whether or not the following salts would dissolve in water (be sure to give the rule you used to make the prediction) A) Potassium Acetate

B) Na2S

C) copper(II) phosphate

D) NH4Cl

E) Silver (I) Iodide

F) BaSO4

G) manganese (II) nitrate

H) CuS

I) Cr(OH)3

J) Ammonium phosphate

Answer 1

The general rules for solubility are:

i) All salts of alkali metals (Li⁺, Na⁺, K⁺, etc) and ammonium (NH₄⁺) are water soluble.

ii) All salts containing nitrate (NO₃^-), acetate (C₂H₃O₂^-), chlorate (ClO₃^-) and perchlorate (ClO₄^-) are soluble in water.

iii) All chloride (Cl^-), bromide (Br^-) and iodide (I^-) salts, except those of Pb²⁺, Ag⁺ and Hg₂²⁺, are soluble. HgI₂ is insoluble.

iv) All fluoride (F^-) salts, except those of Mg²⁺, Ca²⁺, Sr²⁺, Ba²⁺ and Pb²⁺, are soluble.

v) All sulfate (SO₄^2-) , except those of Ca²⁺, Sr²⁺, Ba²⁺, Pb²⁺, Ag⁺ and Hg₂²⁺, are soluble.

vi) All hydroxide (OH^-) and oxide (O^2-) salts, except those of alkali metals and ammonium, are insoluble.

vii) All sulfide (S^2-) salt, except those of alkali metals, ammonium and Ba²⁺, are insoluble.

viii) Carbonates (CO₃^2-), phosphates (PO₄^3-), chromate (CrO₄^2-) and oxalate salts, except those of alkali metals and ammonium, are insoluble.

A) Potassium acetate is soluble by rules (i) and (ii).

B) Na₂S is soluble in water by (i).

C) Copper (II) phosphate is insoluble in water by rule (viii).

D) NH₄Cl will dissolve in water by rules (i) and (iii).

E) Silver (I) iodide will not dissolve in water as per rule (iii) above.

F) BaSO₄ is insoluble in water as per rule (v) above.

G) Manganese (II) nitrate is water soluble as per rule (ii).

H) CuS is insoluble in water according to rule (vii).

I) Cr(OH)₃ is insoluble in water.

J) Ammonium phosphate will dissolve in water as per rule (i).