Determining Spontaneity in the Reaction COCl2(g) -> CO(g)+Cl2(g)

[lha08]

COCl2(g) --> CO(g)+Cl2(g)

Homework Statement

Consider the reaction carried out at 25 degrees celsius and 1 atm: COCl2(g)-->CO(g)+Cl2(g)
In what temperature range will the reaction become (or not become) spontaneous?

Homework Equations

3. The Attempt at a Solution [/b
My hunch is that i have to use ΔG=ΔH-TΔS and set ΔG equal to zero but then I'm not sure how am i supposed to get a temperature range...help please!

 

[Mapes]

Your hunch is correct. The temperature range would be bounded by ΔG=0 and also any temperature at which the components are eliminated: e.g., the boiling temperature of the gases, the dissociation temperature of CO, etc. I'm not sure any of these will be relevant, but it might explain why there's a limited temperature range.

 

[lha08]

Your hunch is correct. The temperature range would be bounded by ΔG=0 and also any temperature at which the components are eliminated: e.g., the boiling temperature of the gases, the dissociation temperature of CO, etc. I'm not sure any of these will be relevant, but it might explain why there's a limited temperature range.

How do we know whether the temperature will be above or below that of the temperature that is bounded by ΔG=0?

 

[Mapes]

I don't know. It's something you have to check, just as if you were designing an industrial process to run the reaction.

 

[cadillac]

I think you'll need extra information, especially the enthalpy of formation for each species, or the entropy of formation. then you can find T