On an exam I got this question:(adsbygoogle = window.adsbygoogle || []).push({});

[PLAIN]http://img849.imageshack.us/img849/5732/spontaneity.png [Broken]

but at the time I had no idea how to answer it. I still don't really know if I can answer it. I can explain it mathematically with the equation:ΔG = ΔH - TΔSseeing as a spontaneous reaction requires a negative change in G and therefore if the sign of ΔH and ΔS are different then temperature will be a determining factor as to whether or not ΔG will be negative. I have no idea what I would need to plot on a graph though. As for examples of reactions of each type I suppose I needed to have a few example reactions memorised.

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Explaining why some reactions are spontaneous at certain temperatures

**Physics Forums | Science Articles, Homework Help, Discussion**