- #1
Mayan Fung
- 131
- 14
When I studied chemistry in high school, I learned that if the change of enthalpy of a reaction ΔH > 0 , the reaction is endothermic, and if ΔH<0, it is exothermic.
However in thermodynamic class, I learnt:
$$ ΔG = ΔH - TΔS $$
For a reaction of a battery, the data reads
ΔG = -394kJ/mol. (which is also the electrical work by the battery), ΔH = -316kJ/mol.
The book then said that the difference (78kJ/mol.) comes from absorbing heat from the environment. So is this an endothermic reaction? However, ΔH<0. Is the system in fact absorbing heat or releasing heat?
Thanks!
However in thermodynamic class, I learnt:
$$ ΔG = ΔH - TΔS $$
For a reaction of a battery, the data reads
ΔG = -394kJ/mol. (which is also the electrical work by the battery), ΔH = -316kJ/mol.
The book then said that the difference (78kJ/mol.) comes from absorbing heat from the environment. So is this an endothermic reaction? However, ΔH<0. Is the system in fact absorbing heat or releasing heat?
Thanks!