## What does it mean for a reaction to be "thermodynamically favored?"

$\Delta G^{\circ}= \Delta H^{\circ} - T \Delta S^{\circ}$

$\Delta G^{\circ}= -RT\ln K$

$\Delta G^{\circ}= \sum \Delta G_{f}^{\circ}(products) - \sum \Delta G_{f}^{\circ}(reactants)$

Posts: 96
Joined: Fri Sep 29, 2017 7:04 am

### What does it mean for a reaction to be "thermodynamically favored?"

I saw somewhere that reactions with a negative enthalpy change are exothermic and thus more favorable than reactions with a positive enthalpy change (endothermic).
But according to the 2nd Law of Thermodynamics (states that reactions tend to go from low to high entropy) then why is a reaction with a negative enthalpy change favorable?

Ishita Monga 1B
Posts: 31
Joined: Thu Jul 27, 2017 3:00 am

### Re: What does it mean for a reaction to be "thermodynamically favored?"

Whether or not a reaction is favored is determined by deltaG. You have to use the relation deltaG=deltaH - TdeltaS in order to determine favorability. If a reaction has a negative enthalpy and entropy increases over the course of the reaction, then a negative minus a positive is still negative. Thus, deltaG would be negative which means that the reaction is favorable.

Cristina Sarmiento 1E
Posts: 52
Joined: Wed Nov 16, 2016 3:02 am

### Re: What does it mean for a reaction to be "thermodynamically favored?"

Reactions that do not require energy are seen as more favorable. Since exothermic reactions release energy and endothermic reactions require energy, exothermic reactions are more favorable.

Angela G 2K
Posts: 30
Joined: Fri Sep 29, 2017 7:06 am

### Re: What does it mean for a reaction to be "thermodynamically favored?"

Enthalpy tends to go from high enthalpy to low enthalpy, whereas entropy tends to go from low entropy to high entropy.
Delta H -, Delta S + = favored
Delta H -, Delta S - = favored at low temperatures only
Delta H +, Delta S + = favored at high temperatures only
Delta H +, Delta S - = not favored (reverse reaction is thermodynamically favored)

Shreya Ramineni 2L
Posts: 50
Joined: Fri Sep 29, 2017 7:07 am

### Re: What does it mean for a reaction to be "thermodynamically favored?"

Thermodynamically favorable means spontaneous, or that the reaction does not require energy in order to happen.

Phillip Winters 2F
Posts: 50
Joined: Fri Sep 29, 2017 7:05 am

### Re: What does it mean for a reaction to be "thermodynamically favored?"

A reaction if thermodynamically favorable if delta G is negative, which means that the reaction is spontaneous and thus doesn't require energy to occur

Kevin Tabibian 1A
Posts: 42
Joined: Fri Sep 29, 2017 7:06 am

### Re: What does it mean for a reaction to be "thermodynamically favored?"

It means that it is energetically favorable and naturally occurring ( spontaneous). This is represented by a negative delta G