Question

I am in a engineering chemistry class and needed to check my answers, please show all details with finding molecular,ionic,net ionic and spectator ions. thank you

5. Write molecular, ionic, and net ionic equations and spectator ions for the following reactions. (a) a magnesium nitrate solution is mixed with a sodium hydroxide solution Molecular equation:- lonic equation: Net ionic equation: Spectator lons: (b) a hydrobromic acid solution and a barium hydroxide solution Molecular equation: Ionic equation: Net ionic equation: Spectator lons: (c) a carbonic acid solution and a sodium hydroxide solution Molecular equation: Ionic equation: Net ionic equation: Spectator lons: (d) a hydrochloric acid and sodium carbonate Molecular equation: Ionic equation: Net ionic equation: Spectator Ions:

Answer 1

The chemical reaction of two aqueous soluble salts undergoes double displacement reaction where the ions of both the salts get exchanged after getting dissociated in the solution and form two new salts. i.e

Now Spectator ions are those ions those are present in solution, but dont take part in the reaction. Generally the common ions present in the Ionic equation are the Spectator ions. And once we omit these spectator ions from Ionic equation, we get the Net Ionic equation

1-

Molecular equation-   Mg(NO3)2(aq) + 2NaOH(aq) ----------------> Mg(OH)2(aq) + 2NaNO3(aq)

Ionic equation- Only the aqueous soluble salts will dissociate into constituent ions and the other remain as precipitate. Now since here all the ions present are aqueous soluble, so all will dissociate

Mg+2(aq) + 2(NO3)-(aq) + 2Na+(aq) + 2OH-(aq) ----------------> Mg+2(aq) + 2OH-(aq) + 2Na+(aq) + 2(NO3)-(aq)

Net ionic equation- Now cancelling the common ions from sides, we get the net ionic equation i.e

Since all of them will be cancelled, so No reaction takes place here

So spectator ions are - Mg+2(aq) , 2(NO3)-(aq) , 2Na+(aq) , 2OH-(aq)

2-

Molecular equation- 2HBr(aq) + Ba(OH)2(aq) ----------------> Ba(Br)2(aq) + 2H2O(l)

Ionic equation- Only the aqueous soluble salts will dissociate into constituent ions and the other remain as precipitate.

2H+(aq) + 2Br-(aq) + Ba+2(aq) + 2OH-(aq) ----------------> Ba+2(aq) + 2Br-(aq) + 2H2O(l)

Net ionic equation- Now cancelling the common ions from sides, we get the net ionic equation i.e

2H+(aq) + 2OH-(aq) ----------------> 2H2O(l)

So spectator ions are - Br-(aq) , Ba+2(aq)

3-

Molecular equation- H2CO3(aq) + 2NaOH(aq) ----------------> Na2CO3(aq) + H2O(l)

Ionic equation- Only the aqueous soluble salts will dissociate into constituent ions and the other remain as precipitate.

2H+(aq) + CO32-(aq) + 2Na+(aq) + 2OH-(aq) ----------------> 2Na+(aq) + CO32-(aq) + 2H2O(l)

Net ionic equation- Now cancelling the common ions from sides, we get the net ionic equation i.e

2H+(aq) + 2OH-(aq) ----------------> 2H2O(l)

So spectator ions are - CO32-(aq) , Na+(aq)

4-

Molecular equation- 2HCl(aq) + Na2CO3(aq) ----------------> 2NaCl(aq) + H2O(g) + CO2(g)

Ionic equation- Only the aqueous soluble salts will dissociate into constituent ions and the other remain as precipitate.

2H+(aq) + 2Cl-(aq) + 2Na+(aq) + CO32-(aq) ----------------> 2Na+(aq) + 2Cl-(aq) + H2O(g) + CO2(g)

Net ionic equation- Now cancelling the common ions from sides, we get the net ionic equation i.e

2H+(aq) + CO32-(aq) ----------------> H2O(g) + CO2(g)

So spectator ions are - Na+(aq) , Cl-(aq)