Non Spontaneous Reaction vs Spontaneous Reverse Reaction


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Michelle Lee 2E
Posts: 64
Joined: Thu Jul 27, 2017 3:01 am

Non Spontaneous Reaction vs Spontaneous Reverse Reaction

Postby Michelle Lee 2E » Sat Jan 27, 2018 10:37 pm

When entropy increases, the reaction is spontaneous. That means (delta)S is positive. When (delta)S is negative, would that mean the reverse reaction is spontaneous? If so, how should we think of the difference between a non spontaneous reaction and just a reverse reaction that is spontaneous?

When I say reverse reaction, I'm referring to products becoming reactants.

Curtis Tam 1J
Posts: 105
Joined: Thu Jul 13, 2017 3:00 am

Re: Non Spontaneous Reaction vs Spontaneous Reverse Reaction

Postby Curtis Tam 1J » Sat Jan 27, 2018 10:45 pm

I think you don't really need to think in terms of forward or reverse reactions. Just know that in any reaction, it will tend to proceed in a certain way. If the forward reaction doesn't proceed spontaneously, then I believe it should be spontaneous in the reverse direction.

Srbui Azarapetian 2C
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Re: Non Spontaneous Reaction vs Spontaneous Reverse Reaction

Postby Srbui Azarapetian 2C » Sun Jan 28, 2018 1:58 pm

In the forward reaction if entropy was positive and enthalpy negative, the reaction is spontaneous at all temperatures. In the case of the same reaction, except the reverse, the reaction would have negative entropy and enthalpy positive, which is the most unfavorable set of conditions, meaning the reaction is not spontaneous.


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