When a solution of nickel (II) chloride is mixed with a stoichiometric amount of colorless sodium hydroxide solution, a green, gelatinous precipitate forms.

(a) Write the balanced molecular equation and the net-ionic equation for this reaction.

molecular: Ni(Cl)2 (aq) + NaOH (aq) -> Ni(OH)2 (aq) + NaCl
net-ionic: Cl^- -> OH^-

I am pretty sure that I did this wrong. Could someone please help?

(b) What would you expect to observe if some hydrobromic acid solution was added to the reaction mixture in (a)? Be specific. Include equations for any secondary reactions occurring.

You didn't balance the molecular equation. Balanced it is

molecular: Ni(Cl)2 (aq) + 2NaOH (aq) -> Ni(OH)2 (aq) + 2NaCl

The net ionic equation is
Ni^2+(aq) + 2OH^-(aq) ==> Ni(OH)2(s)

You get that by writing the molecular equation as ions UNLESS the material is a solid, gas, or slightly ionized.
Ni^2+(aq) + 2Cl^-(aq) + 2Na^+(aq) + 2Cl^-(aq) ==>Ni(OH)2(s) + 2Na^+(aq) + 2Cl^-(aq)
Now cancel the spectator ions; those are the ions that appear on both sides of the equation. The 2Cl^-(aq) cancel; the two 2Na^+(aq) ions cancel to leave the net ionic equation I wrote above.

If HBR was added, would water form?

HBr (aq) + NaOH (aq) -> H2O (l) + NaBr (aq)

(a) Your molecular equation is correct:

Ni(Cl)2 (aq) + 2NaOH (aq) -> Ni(OH)2 (s) + 2NaCl (aq)

However, your net ionic equation is not quite accurate. The correct net ionic equation should show the dissociation of the compounds into their respective ions:

Ni^2+ (aq) + 2OH^- (aq) -> Ni(OH)2 (s)

(b) If hydrobromic acid (HBr) solution is added to the reaction mixture, you would expect the following secondary reactions to occur:

1. In solution:
HBr (aq) -> H+ (aq) + Br^- (aq)

2. Reaction with nickel hydroxide:
Ni(OH)2 (s) + 2H+ (aq) -> Ni^2+ (aq) + 2H2O (l)

Overall, the addition of hydrobromic acid would result in the dissolution of the nickel hydroxide precipitate and the formation of a new solution containing nickel ions and bromide ions.

To determine what would happen if hydrobromic acid (HBr) solution was added to the reaction mixture, we need to consider the possible reactions that could occur.

First, let's write the balanced molecular equation for the reaction between hydrobromic acid (HBr) and sodium hydroxide (NaOH):

HBr (aq) + NaOH (aq) -> NaBr (aq) + H2O (l)

Now, let's consider how this reaction would affect the green, gelatinous precipitate formed earlier. Nickel hydroxide (Ni(OH)2) is an amphoteric substance, meaning it can react with both acids and bases.

In the presence of hydrochloric acid (HCl), the following reaction can occur:

Ni(OH)2 (s) + 2HCl (aq) -> NiCl2 (aq) + 2H2O (l)

Similarly, in the presence of hydrobromic acid (HBr), the following reaction can occur:

Ni(OH)2 (s) + 2HBr (aq) -> NiBr2 (aq) + 2H2O (l)

Therefore, if hydrobromic acid solution is added to the reaction mixture, it would react with the green, gelatinous precipitate (nickel hydroxide) and form a solution of nickel bromide (NiBr2) and water. The green color of the precipitate would likely disappear.

To summarize:

Reaction between HBr and NaOH:
HBr (aq) + NaOH (aq) -> NaBr (aq) + H2O (l)

Reaction between Ni(OH)2 and HBr:
Ni(OH)2 (s) + 2HBr (aq) -> NiBr2 (aq) + 2H2O (l)