[laxplayer]

okay, the question says "When the following solutions are mixed together, what precipitate (if any) will form?" and the problem is "Al(NO3)3 (aq) + Ba(OH)2 (aq)"
i got the results to be Al(OH)2 and Ba(NO3)3 and i don't think either of those are a precipitate. I am using the precipitation diagram where it shows the rows of cations and columns of anions. Am I doing anything wrong because when I enter those answers they are incorrect, and when I put "none" it also comes out as incorrect. 

[Sev]

i got the results to be Al(OH)2 and Ba(NO3)3 and i don't think either of those are a precipitate.

Aluminium hydroxide is Al(OH)₃, Barium nitrate is Ba(NO₃)₂.  One of these will ppt out of soln.
Hint: nitrates are soluble.

[laxplayer]

oh, can you explain to me why the subscripts are 3 and 2 rather than what I got?

[Mitch]

Aluminum has an oxidation state of +3, while hydroxide(-OH) has an oxidation state of -1.

[laxplayer]

so is this a redox reaction?

[Sev]

so is this a redox reaction?

No, since the oxidation states don't change.

[laxplayer]

then i still don't get why you change the subscripts

[enahs]

then i still don't get why you change the subscripts

Aluminum typically carries a 3⁺ charge. OH^- carries a -1 charge. To form the stable precipitate it has to be neutral (no charge). Therefor to make the solution neutral you need 3 OH^- for every for every 1 Al³⁺ ((+3) + (3*(-1)) = 3-3 = 0.


Quick search turned this up, give it a read over:
http://www.chemistry.co.nz/chemequa.htm

[laxplayer]

i get it now, thanks :]