I do not believe in the correctness ofyour assumption
T= ((Delta H^o)/(Delta S^o))
They should have told you what temperature to assume. delta S^o values are usually quoted for 298 K.
I agree with your
K= e^(-(DeltaG^o)/RT)
and your delta S and delta H calculations, but I am rusty on this subject after 45+ years
Our resident chemical expert is still away, and so it is possible that you won't be getting any other responses to this soon.
Given the thermodynamic data in the table below, calculate the equilibrium constant for the reaction:
2SO2(g)+O2--> 2SO3
Substance (DeltaH^o) (Delat S^o)
SO2 -297 249
O2 0 205
SO3 -395 256
Answer (it was given) 2.32x10^24
Even though the answer is given (2.32x10^24) I just can't get there. I calculated:
(Delta H^o)= ((2moles)(-395))-((2moles)(-297)+(1mole)(0))=-196
(Delta S^o)= ((2moles)(256))-((2moles)(249)+(1mole)(205)=-191
From here I thought: If I need to find the equilibrium constant K, I can use the formula (Delta G^0)= -RT ln K and thus K= e^(-(DeltaG^o)/RT)
To get there I figure I would need to find (Delta G^o)...which is possible because I do have (Delta H^o) and (Delta S^o) and I can use the formula
(Delta G^o)= (Delta H^o) - T(Delta S^o) ...I assumed that the temperature is 298K and that didn't work and then I calculated T (T= ((Delta H^o)/(Delta S^o))...I get 1026K and then I put that into (Delta G^o)= (Delta H^o) - T(Delta S^o)...and then solved all the rest but that doesn't work out either. Could you tell me were I am wrong or write down how you would solve the problem?
Thank You!!
2 answers
a little lat ebut i do believe you forgot to put delta s into kJ as the base unit is joules