[Broken_logic]

Hello everyone. 

I have the reaction 2HgO = 2HG + O2.

I need to determine the dissociation T with the following data:

Delta H of reaction = 181,580 J/mol (already corrected for coefficients)
Delta S of reaction = 216.45           "                                         "
pressure of 1 bar  fO2 = 1 bar.

The instructions say Delta H and Delta S can be taken as independent of T

I wanted to check this answer.  I decided to use Delta G = Delta H - T * Delta S
I set Delta G = 0 so we are on the equilibrium curve for the reaction (i.e. 2Hgo is going
to 2 HG's and O2).  Then solving for T. 
My calculation is: 181,580/216.45 T= 838.90 Kelvin or 565 C. 

I found at another source that the dissociation should take place around 500 so my
value may be a little High... Am i right to set Delta G to 0 and solve for T using
Delta H and Delta S?

Thanks so much!