Testing for nitrate
 

When testing for nitrate, aluminium and NaOH is add to the test substance and heat it, the aluminium will first react with the NaOH to give hydrogen and the hydrogen reduce the nitrate to ammonia.

When aluminium react with NaOH, what is the other product except hydrogen???

Al + NaOH --------> H2 + ?????????

can anyone tell me?

Sodium aluminate (ionic)

In solution Na+(aq) and Al[(H2O)2(OH)4]-(aq) ions

Aluminate ion is Al(OH)4(-).

The aluminate ion is basically (no pun intended) the hexaaqua aluminium III ion with four protons removed from four of the water molecules...

thus [Al(H2O)6]3+ ---> Al[(H2O)2(OH)4]- +4H+

or if you show then being removed by base (more correct)

[Al(H2O)6]3+ + 4OH- ---> Al[(H2O)2(OH)4]- +4H2O

I didn't mean to correct you. I didn't realize you had posted the structure of the ion, so I looked it up on the internet to clarify your post for the reader. I got the structure I posted from here after a brief Google search:

http://www.uncp.edu/home/mcclurem/ptable/al.htm

I myself know nothing about aluminate ions.