Is it possible for reactions that are with delta G0 and at the same time endothermic delta H0 and delta S

Question

Is it possible for reactions that are with delta G>0 and at the same time endothermic delta H>0 and delta S<0 to take place?

jfraser · Answer

If DG is greater than zero, the reaction will not be spontaneous. The way the Gibbs' equation works,$$\Delta G = \Delta H - T \Delta S$$If DH is positive, and DS is negative, then
$$\Delta G = (+) - T(-)$$
the minus TDS becomes a positive value, and DG will never become negative, no matter what temperature you try to run the reaction at.

anonymous · Answer

OK, then how do you explain the conversion of graphite into diamond which is endothermic reaction and at the same time TDS<0? We can see that ΔG>0 no matter the temperature

jfraser · Answer

The conversion of graphite into diamond happens at extreme combinations of pressure as well as temperature, and requires a whole lot of work to accomplish.

the DG for C(diamond) --> C(graphite) is negative, i've done that calculation many times.

anonymous · Answer

JFraser would you mind giving me a hand please when you finish with him. http://openstudy.com/study?login#/updates/4f6b1c95e4b014cf77c7fd88

anonymous · Answer

Still you didn't answer my question. If you don't know just don't. I'm not asking about the conversion of diamond into graphite because this is the favorable reaction and I'm asking about graphite --> diamond...