# Chemistry: Prediction of producs

1. Nov 1, 2009

### markelmarcel

1. The problem statement, all variables and given/known data
Predict products (and then write formula unit, total ionic unit & net ionic equations)

1. Sodium Nitrate, Ammonium sulfate and Iron (III) acetate.

2. Na3PO4 + RbClO3 + Sr(NO3)2

2. Relevant equations

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3. The attempt at a solution

1. NaNO3 + (NH4)2S + Fe(CH3CO2)3

I just don't know how to decide what parts will be "spectator ions" and how the 3 products will work out.... I know it deals with acids and bases, but my prof went through it really fast and I tried reading our textbook but it didn't help very much with the 3 reactants, and he went out of town for a conference so I couldn't ask him for help....

I think that Fe and S will come together to make a precipitate which would be Fe2S3 and then I'm assuming that the NH4CH3CO2 would then combine together, leaving the NaNO3 as the spectator ions?

2. Nov 1, 2009

### Staff: Mentor

Sulfate or sulfide? Sulfide precipitation is a good idea. Similar approach will work for the second question - just think, what combination of ions will produce something insoluble. And don't overdo - ammonium acetate will be just a spectator.

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methods

3. Nov 1, 2009

### markelmarcel

ah, touche! it is sulfate- don't know why when i typed it out i made it into sulfide. i was doing my own chemistry ;)

4. Nov 2, 2009

### markelmarcel

Ok so for the first one I got...

NaNO3 + 3(NH4)2SO4 + 2Fe(CH3CO2)3 $$\rightarrow$$ Fe2(SO4)3 [/SUB](s) + 6NH4CH3CO2

When I looked up what I had for my solubility rules I found
Na3PO4, RbClO3 and Sr(NO3)2 to all be soluble... So where do I go from here? Randomly place things together??

5. Nov 2, 2009

### Staff: Mentor

Iron (III) sulfide is insoluble, but sulfate is soluble. No reaction if you ask me.

In the second question one of the combinations of cation and anion give insoluble salt.

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methods

6. Nov 2, 2009

### markelmarcel

Ok I'm still working on balancing but for the second I'm assuming the insoluble salt has to be Sr3(PO4)2

Because PO4 is insoluble, as is Sr (with it being a group II cation).

7. Nov 3, 2009

### Staff: Mentor

Like calcium and barium phosphates and sulfates.

No such thing as insoluble PO4 - it is PO43- and it never exists without counterion.

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