Compound stability with respect to decomposition

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

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

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

Sierra Cheslick 2B
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Joined: Fri Sep 28, 2018 12:27 am

Compound stability with respect to decomposition

Why does having a negative deltaG make a compound unstable with respect to decomposition?

Neil Hsu 2A
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Joined: Fri Sep 28, 2018 12:16 am

Re: Compound stability with respect to decomposition

Looking at a decomposition reaction, let's say A --> B + C, if the reaction has a negative delta G, then the decomposition reaction is spontaneous, or favorable. This means that A has a tendency to decompose into B and C; in other words, we can say that A is unstable.

Albert Duong 4C
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Re: Compound stability with respect to decomposition

I believe because a negative delta g indicates that a reaction is spontaneous (more likely to occur or favorable), and if that compound is unstable it means that its more likely to revert back to its pure elements (hence, decomposition).

Kelsey Warren 1I
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Joined: Fri Sep 28, 2018 12:15 am

Re: Compound stability with respect to decomposition

If delta G is negative, then the forward reaction is favored, which means that the reactants are unstable and will decompose into the products spontaneously.