sodium percarbonate

[coke]

how good of an oxidizer is powdered sodium percarbonate? It's available very easily as detergent/stain remover.

 

First off, its 2 sodium bicarbonate molecules in crystalline structure with 3 hydrogen peroxides. It releases 3 hydrogen peroxides in water. We all know hydrogen peroxide is a good oxidizer, so say if you mixed powdered sodium percarbonate with powdered aluminum, would you get a thermite type reaction?

 

Also, if you mix it with only a tiny amount of water, can you get like 50% H2O2?

[Theophrastus]

In regards to your question, I'll say the following, implying the facts on the wikipedia page to be correct. Knowing that sodium percarbonate decomposes to form peroxide and sodium carbonate, in an aqueous solution, technically speaking, the oxidiser in question, is really the peroxide, and thus, one can assume that its strength as an oxidiser is equal to hydrogen peroxide, as that is really what you are refering to. To your second question, I sadly have to say no. You see, what occurs in such a reaction is that the peroxide breaks down to form oxygen and water. The oxygen is then taken by aluminum to form aluminum oxide. It does not occur in a one- step single- displacement redox reaction where the aluminum "steals" the oxygen, from the peroxide. Rather, it is willingly donated, in the decomposition of the peroxide.

 

2(Na2CO3- 1.5H2O2) > 2Na2CO3 + 3H2O2

H2O2 > H2O + O

2Al + O2 + O > Al2O3

 

Technically, the rusting of the aluminum metal releases just as much heat as the burning of acetylene gas, however this heat is released over such a prolonged period of time, that there would be no noticeable effects, and as such, would not lead to instantaneous thermite- esque heat. I recommend looking up reaction kinetics, and the like. Cheers!

Edited April 17, 2009 by Theophrastus
Addition of content. (and correction of grammar)