## Rate of Entropy Generation

$\Delta S = \frac{q_{rev}}{T}$

kshalbi
Posts: 68
Joined: Fri Sep 25, 2015 3:00 am

### Rate of Entropy Generation

Can the rate of entropy generation be negative?

Austin Qiu 1A
Posts: 21
Joined: Fri Sep 25, 2015 3:00 am

### Re: Rate of Entropy Generation

Hm I would answer yes, because I know that in many reactions that involve a greater number (mols) of reactants that generate fewer mols of products. Since the total number of molecules of the system decreases, the change in entropy will be negative.

Alexander Vong 3I
Posts: 56
Joined: Fri Sep 25, 2015 3:00 am

### Re: Rate of Entropy Generation

Entropy, being a measure of disorder, can change when the reactant undergoes a phase change. If the reactant changes from a gas to a liquid, the entropy decreases, because a substance is more disordered as a gas than as its liquid.

Alexander Vong 3I
Posts: 56
Joined: Fri Sep 25, 2015 3:00 am

### Re: Rate of Entropy Generation

Keep in mind, heat transfer can change entropy. If heat leaves a system, the entropy decreases. Considering that the entropy of the universe is zero, somewhere else there has to be an entropy change that is positive to balance out the first entropy change.