[rajiv]

Dear All,

Recently i got Trisodium Phosphate (Na3PO4) and tried to do some reaction with this but i didn't get much success. Then i tried to do electrolysis for the same by using 9V current.

1. Firstly i used iron electrode for electrolysis of aqueous solution of TSP (trisodium phosphate) and observed formation of some greenish precipitate on one electrode and some bubbling of gas on another electrode. I guess greenish precipitate must be hydroxide of iron which is generating on that electrode.

2. Secondly i used copper wire as electrode for same material and observed bluish precipitate on that electrode. That must be copper hydroxide forming on that electrode.


Now i am not getting the idea of what is the gas coming out in another electrode and what is the solution formed in the container.  What i guess sodium may be generating on that electrode is reacting with metal electrode (Fe and Cu) to form there hydroxides. Can anybody suggest the reactions going on and for products forming in the reaction vessel.

[Arkcon]

It appears you're working from a water solution, and not fused salts.  So you can forget about sodium being produced.  There are two reasons for that, one should be obvious, and the other requires some knowledge of electrochemistry.  As to the identity of the gas, you can test for some likely suspects, if you collect a test tube full.  And you can look up those.  If you understand electrochemistry, you can try to write out red-ox half reactions to determine what the gases are.

[AWK]

During electrolysis of salts you may expect: decomposition of cation (eg Cu²⁺ to Cu, Ag⁺ to Ag), and/or decomposition of anion (eg. Cl^- to gaseous chlorine), or electrolysis of water.

[rajiv]

Thanks for all replies..

I just want to know copper/ Iron is dissociated from electrode to form hydroxides with TSP whereas same thing is not happening with NaOH solution.

                                           Can i collect this metal hyroxide (CuOH2) to form its chlorides or sulphates ?