## deltaS total spontaneity question 9.73

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

Paula Dowdell 1F
Posts: 72
Joined: Tue Nov 15, 2016 3:00 am

### deltaS total spontaneity question 9.73

Hi!

This relates to question 9.73 in the book: "Under what conditions, if any, does the sign of each of the following quantities provide a criterion for assessing the spontaneity of a reaction? (a) G ; (b) H ; (c) S ; (d) delta S total"

I thought that if delta S total was negative the reaction would be considered spontaneous, but the solutions manual says if delta S total> 0, it is spontaneous.

Can someone explain this to me? Thanks!

JamesAntonios 1E
Posts: 70
Joined: Fri Sep 29, 2017 7:04 am

### Re: deltaS total spontaneity question 9.73

Paula Dowdell 1F wrote:Hi!

This relates to question 9.73 in the book: "Under what conditions, if any, does the sign of each of the following quantities provide a criterion for assessing the spontaneity of a reaction? (a) G ; (b) H ; (c) S ; (d) delta S total"

I thought that if delta S total was negative the reaction would be considered spontaneous, but the solutions manual says if delta S total> 0, it is spontaneous.

Can someone explain this to me? Thanks!

Yeah. This is different than delta G. Remember that delta G includes -TdeltaS. That negative sign is opposite in the delta S>0. Delta S>0 for a spontaneous reaction because the universe naturally goes to disorder.