Question

In many chemical reactions of two or more compounds, ions are present in the solution that do not participate in the reaction. These ions, known as spectator ions, can be removed from the chemical equation describing the reaction. A chemical equation that has the spectator ions removed is known as a net ionic equation.

Reactions between ionic compounds often result in the precipitation of an insoluble compound. Spectator ions and precipitation products of a chemical reaction can be predicted by consulting an ionic substance solubility table. Here is one such table:

Rule	General trend
1	Most salts containing alkali metal or ammonium (NH4+)(NH4+) cations are soluble.
2	Most salts containing NO3−NO3− are soluble.
3	Most salts containing Cl−Cl− , Br−Br− , and I−I− are soluble, except with metals such as Ag+Ag+ , Pb2+Pb2+ , and Hg2+Hg2+ .
4	SO42−SO42− salts with +1 cations and Mg2+Mg2+ are soluble, but with most +2 cations these salts are insoluble.
5	Most compounds with OH−OH− anions are not soluble. Notable exceptions are compounds of the alkali metals, ammonium, calcium, strontium, and barium.

Entering chemical equations

When entering chemical equations, please follow the following formatting guidelines

• Add phases to all chemical reactions unless asked otherwise. When adding phases, make sure not to place them as a subscript.
• Do not stack charges and subscripts. To add a charge to an ion with a subscript, first enter the subscript. For example, to type SO42−SO42− start by typing SO₄ . Then use the arrow key to arrow over before adding a superscript with the charge.

If you make a formatting error, you will see an message such as "Check your placement of subscripts and superscripts." or "There is an error in your submission. Make sure you have formatted it properly." You will not lose any credit, but the answer will need to be edited and re-submitted.

a.) What is the net ionic equation of the reaction of ZnCl2 with NaOH ?

Express your answer as a chemical equation.

b.) What is the net ionic equation of the reaction of MgSO4 with BaCl2 ?

Express your answer as a chemical equation.

Answer 1

Answer a):-

​​​​​​The balanced chemical equation for the reaction between ZnCl₂ and NaOH :

ZnCl₂ (aq) + 2 NaOH (aq) Zn(OH)₂ (s) + 2 NaCl (aq)

Total ionic equation:-

Zn²⁺ (aq) + 2 Cl^- (aq) + 2 Na⁺ ​​​​​​(aq) + 2 OH^- (aq) Zn(OH)₂ (s) + 2 Na​​​​​​​⁺ (aq) + 2 Cl^- (aq)

Eliminating spectators ions from total ionic equation, we get net ionic equation:-

Zn²⁺ (aq) + 2 OH^- (aq) Zn(OH)₂ (s)

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_{​​​​​​}Answer b):-

​​​​​​The balanced chemical equation for the reaction between MgSO₄ and BaCl₂ :

MgSO₄ (aq) + BaCl₂ (aq)   MgCl₂ (aq) + BaSO₄ (s)

Total ionic equation:-

Mg²⁺ (aq) + SO₄^2- (aq) + Ba²⁺ (aq) + 2 Cl^- (aq) Mg²⁺ (aq) + 2 Cl^- (aq) + BaSO₄ (s)

Eliminating spectators ions from total ionic equation, we get net ionic equation:

Ba²⁺ (aq) + SO₄^2- (aq)   BaSO₄ (s)

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