Reaction Hydrogen Peroxide

[raden gurnanda]

Hi, there...

 

i need your kind help to solve this problem, its about reaction decomposition of hydrogen peroxide..

 

which is true?

 

(i) H2O2(l) → H2O(l) + O(g)

 

or

 

(ii) 2H2O2(l) → 2H2O(l) + 2O2(g)

 

the former reaction produce monoatomic oxygen, named On , and act as oxidizing agent. (could anyone tell how strength is it?)

while, the latter reaction is common reaction..

 

what the eligibility for both reaction..?

 

thanks a lot for your prompt attention to this matter..

sincerely,

 

Nanda

-Dept.Physical Chem. Padjadjaran University, Indonesia-

[Enthalpy]

Hi Nanda, welcome here!

 

Enthalpy of formation :

-188kJ/mol peroxide

-286kJ/mol water

+249kJ/mol atomic oxygen

so I'd say atomic oxygen won't form from spontaneous decomposition.

 

The real situation must be less direct. Decomposition must proceed around other compounds like traces of organic substances, mineral dust (this is a known condition for peroxide storage)... through multistep reactions. And even if no other compound were available, cosmic rays would act.

 

So I'd say

"Form monoatomic oxygen which then reacts" no;

"React with a different compound where a single peroxide can give a single oxygen atom" yes, and it likely precedes the formation of oxygen molecules if any.

 

Let's see what chemists say.

[raden gurnanda]

thanks a lot for your explanation...

so, reaction (i) is unspontaneous reaction and it required the conditions as you mentioned above....

 

mmmm, then..if i use H2O2 alone -without any catalyst within- in order to treat the wastewater (remove its organic pollutant ), which reaction would be occured?

do you think that On (monoatomic oxygen) could be an oxidant for organic substances? since it had two free radical...

how strong is it?

 

 

 

 

 

 

 

 

[Enthalpy]

You will not get atomic oxygen because energy lacks. 147kJ is 59* RT at 300K, impossible.

 

Peroxide will react with the pollutant. The net result is water and some combination of oxygen and the atoms of the pollutant, but this reaction doesn't pass by atomic oxygen.

 

Details of the process are necessarily complicated and depend on the exact pollutant and possible catalysts, so I feel better to ignore them.

[raden gurnanda]

ok i agree it.... but, what the oxidant involve in this reaction? who oxidize the pollutant...?

H2O2...in what form....?

[Enthalpy]

This depends on detailed reaction mechanisms, specific to each target. But don't expect the perodixe to decompose before reaching its target.

[raden gurnanda]

ok... i got it, maybe the reaction will undergo by presence of the catalyst e.g: