Can someone please help with this chem question?

Question

"Using the solubility table, identify the following anions from the information given. Write the net ionic equtions that produce a precipitate.

(a) Its barium salt is insoluble in water but its copper salt is soluble.

(b) Its copper salt is insoluble in water, but its barium salt is soluble.

(c) Its mercury(II) salt is water soluble but its mercury(I) salt is not."

General Solubility Rule for Ionic Compounds in Water

N O 3^−. All compounds are soluble

 CH3COO⁻  All compounds are soluble; borderline CH3COOAg

ClO3⁻ All compounds are soluble

ClO4⁻ All compounds are soluble; boderline KClO4

Cl^– All compounds are soluble except AgCl, Hg2Cl2, PbCl2

Br^– All compounds are soluble except AgBr, Hg2Br2, HgBr2, PbBr2

 I ^– All compounds are soluble except AgI, Hg2I2, HgI2, PbCl2

S O 3^2 − All compounds are soluble except CaSO4, SrSO4, BaSO4, Ag2SO4, Hg2SO4, PbSO4

OH⁻ Most compounds insoluble except Group I metals,NH4+, Sr2+, Ba2+

F^– Most compounds insoluble except Group I metals,  Na+,K+,Rb+,Cs+,NH4+,Al3+

S ^2 – , S O 3^2 −. Most compounds insoluble except Group I metals, NH4+,Ba2+

C O 3^2 – , H C O 3 ⁻  Most compounds insoluble except Group I metals, NH4+

CrO4^2−. Most compounds insoluble except Group I metals, NH4+

PO4^3−. Most compounds insoluble except Group I metals, NH4+

 

Answer 1

When a compound is insoluble, the ions that form it will produce a precipitate when they are placed in solution with each other. To answer this question, you need to find one or more ions from the solubility table that form soluble compounds for the soluble salt in the question and forms insoluble compounds for the insoluble salt in the question.

To write the net ionic equation that forms a precipitate, write the 2 ions on the reaction side (left side) of the equation and the precipitating compound on the product side (right side) of the equation. Write (aq) after each ion to indicate that it is dissolved in water and (s) after the precipitating salt to indicate that it has precipitated out of solution as a solid.

Ion(aq) + ion(aq) → salt(s)

NOTE: Make sure you balance the equation by putting numbers (coefficients)  in front of the ions and the salt as needed to balance both the charge and the number of atoms of each element.

_Ion(aq) + _ion(aq) → _salt(s)

(a) Its barium salt is insoluble in water but its copper salt is soluble.

Clue: See solubility table for S O 3^2 −

Since the Barium salt of SO₃^2- is insoluble, the net ionic equation for its precipitate formation with SO₃^2- is:

         Ba²⁺(aq) + SO₃^2-(aq) →  BaSO₃(s) balanced as written

           

(b) Its copper salt is insoluble in water, but its barium salt is soluble.

Clues: See solubility table for OH⁻,  S ^2 –, S O 3^2 −

Since the copper salts of OH-, S^2-, and SO3^2- are insoluble and copper forms ions Cu^- and Cu^2-, the net ionic equations for the formation of these salts are as follows:

Cu⁺(aq) + OH^-(aq) → CuOH(s)

Cu²⁺(aq) + 2OH^-(aq) → Cu(OH)₂(s)

2Cu⁺(aq) + S^2-(aq) → Cu₂S(s)

Cu²⁺(aq) + S^2-(aq) → CuS(s)

2Cu⁺(aq) + SO₃^2-(aq) → Cu₂SO₃(s)

Cu²⁺(aq) + S^2-(aq) → CuSO₃(s)

(c)  Its mercury(II) salt is water soluble but its mercury(I) salt is not."

Clue: See solubility table for Cl^–

The mercury salt(I) salt is Hg⁺ and the mercury(II) salt is Hg^2+.

Since the mercury(II) salt is soluble and the mercury(I) salt is insoluble, the net ionic equation for the formation of mercury(I) salt of Cl^- is:

2Hg⁺(aq)  + 2Cl^-(aq) → Hg₂Cl₂(s)   This product is written as Hg₂Cl₂ instead of HgCl because it exists as a dimer.

Answer 2

Just use the rules that are elaborated:

The first one: Note that the rules says SO₃^2- incorrectly. Should be SO₄^2-

Look for insoluble Barium salt that is mostly soluble. This leads to sulfate, because they are mostly soluble, except for Barium sulfate.

In the second one, look for anion that is mostly soluble except for Ba: OH^-, SO₃^2-, or S^2-.

I'll let you do third one.