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View Full Version : Activation energy of Silicon Dioxide thermite reaction?


wil3
Sep27-09, 12:12 PM
I am not asking how to make this reaction. Please do not lock this thread just because it happens to contain the word "thermite". I am simply asking for information about this process for research involving silica.

The Goldshmidt process between silicon dioxide and aluminum is expressed by the equation:

http://amazingrust.com/Experiments/how_to/Images/Reaction10_a.gif

I have used a table of standard enthalpies of formation to determine the energy yield per mole of the bare reaction. My question is how can I determine the activation energy of this reaction? Please do not direct me to the Arrhenius rate equation unless you have rate information.

I am mainly interested in the difference between the energy produced per mole and the energy required to sustain the reaction per mole. This reaction is often "boosted" by adding sulfur to the mixture to increase the energy yield through side reactions with the aluminum. I am curious as to why this is necessary, and if it would be thermodynamically possible to carry out the reaction without the use of additives like sulfur.

Any additional information regarding the specific reasons why sulfur addition is necessary would be appreciated.

Thank you in advance for any responses!

Borek
Sep28-09, 07:23 AM
I can't think of any other way of getting the data then checking literature and handbooks (that is, visiting library).

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wil3
Sep28-09, 05:10 PM
What is this "Library" you speak of? How do I do one?

Borek
Sep28-09, 06:21 PM
You know, large rooms, shelves, books and librarian...

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Redbelly98
Sep28-09, 07:34 PM
What is this "Library" you speak of? How do I do one?

You know, large rooms, shelves, books and librarian...

There might be some confusion here, based on the two of you being from different countries.

wil3, Borek probably means a library found in and operated by the chemistry department of a university or other scientific research institution. If you were thinking of a public library that caters to the general public, then no that would be the wrong place to look.

chemisttree
Sep29-09, 11:49 AM
wil3, Borek probably means a library found in and operated by the chemistry department of a university or other scientific research institution...

And while you are there, look for the following article

J. Materials Sci., Vol. 28, No. 14, pps. 3693-3708.

Smile for the cameras...