[Sanapo]

I have to complete these two reactions:

1)  SiO₂  +  C     ...

2)  SiO₂  +  H₂O₂     ...

and estimate the temperature required to make them happen (if they could happen).


I guess:

1)  SiO₂  +  2C     Si  +  2CO

2)  SiO₂  +   2H₂O₂     Si  +  2O₂  +  2H₂O

I don't know if that's correct. Isn't it? How can I estimate the temperature?

[ramboacid]

Assuming that you could look up a table of standard molar enthalpies of formation and entropies of the reactants and products, and that the reactions are correct, you could calculate values of ΔH° and ΔS° for the reactions at standard conditions. Then you could calculate the temperature for which ΔG° is zero, meaning that the reaction will be at least at equilibrium. A negative value of ΔG° means that the reaction will proceed in the forward direction.

The formula relating ΔG° to ΔH° and ΔS° is: ΔG° = ΔH° - TΔS°, where T is temperature in Kelvin.

[AWK]

1. http://en.wikipedia.org/wiki/Silicon
2. You can rather expect decomposition of H₂O₂