what is the total ionic equation for
AlPO4(aq)+3NaOH(aq)=Al(OH)3(s)+ Na3PO4, I am not sure I am right
I have
Al+PO4(aq)+Na3+OH3() --> Al+OH3+Na3+PO4
but then everything crosses itself out and I don't have a net.
what am I doing wrong?
To write the total ionic equation, you need to separate all the compounds into their respective ions. Then, you can determine which ions will combine to form new compounds, and which ions will remain unchanged.
Let's start by breaking down the compounds into their respective ions:
AlPO4(aq): Al^3+(aq) + PO4^3-(aq)
3NaOH(aq): 3Na+(aq) + 3OH-(aq)
Al(OH)3(s): This compound does not dissociate in water, so it remains unchanged.
Na3PO4(aq): 3Na+(aq) + PO4^3-(aq)
Now, we have the ions for each compound. Next, we can determine the products of the reaction by matching the positive and negative ions:
Al^3+(aq) + 3OH-(aq) + 3Na+(aq) + PO4^3-(aq) --> Al(OH)3(s) + 3Na+(aq) + PO4^3-(aq)
As you correctly stated, when we compare the ions on both sides of the equation, we can see that the 3Na+(aq) and PO4^3-(aq) ions are present on both sides. These are called spectator ions and can be eliminated because they are not involved in the actual reaction. Therefore, the net ionic equation would be:
Al^3+(aq) + 3OH-(aq) --> Al(OH)3(s)
In summary, the correct total ionic equation is:
Al^3+(aq) + 3OH-(aq) + 3Na+(aq) + PO4^3-(aq) --> Al(OH)3(s) + 3Na+(aq) + PO4^3-(aq)
And the net ionic equation is:
Al^3+(aq) + 3OH-(aq) --> Al(OH)3(s)
It makes it more complicated but we really should include the charges. Your main problem is that Al(OH)3 is a solid and does NOT break out ions. If you included the phases it might have kept you from making that error.
Al^3+(aq) + PO4^3-(aq) + 3Na+(aq) + 3OH^-(aq) ==>Al(OH)3(s) + 3Na^+(aq) + PO4^3-(aq)
Now when you start crossing out you can't eliminate Al^3+ nor 3OH^- so the net ionic equation is
Al^3+(aq) + 3OH^-(aq) ==> Al(OH)3(s)
Have you memorized the simple solubility rules. That would have told you Al(OH)3 is insoluble. Here is a simplified set of solubility rules.
http://www.files.chem.vt.edu/RVGS/ACT/notes/solubility_rules.html