I am having trouble understanding free energy ( delta G) in a reaction. I know you use based on enthalpy and entrophy to figure it out but I am having trouble grasping the concept. If you could explain it in simple terms I would greatly appreciate it. The questions I have been trying to work through ask me to predict the temperature conditions under which delta G is likely to be negative... here is an example:
H2(g) + Cl2(g) --> 2HCl (g) delta H= -180 kJ/mol
H2(g) + Cl2(g) --> 2HCl (g) delta H= -180 kJ/mol