Why can substances with endothermic heat of solution dissolve?

Thread starter STEMucator
Start date Feb 4, 2014
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Endothermic

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A substance with an endothermic heat of solution can dissolve due to the balance between enthalpy and entropy changes. While the dissolution process absorbs heat, leading to a decrease in temperature, the increase in entropy during the mixing of solute and solvent contributes to the overall spontaneity of the process. The Gibbs free energy change (ΔG) is crucial, as it determines whether a reaction will occur. It is expressed as ΔG = ΔH - TΔS, where ΔH represents the heat absorbed, T is the temperature, and ΔS is the change in entropy. Even with an endothermic reaction, if the entropy increase (ΔS) is significant enough, it can drive the dissolution process forward, making it thermodynamically favorable despite the initial cooling effect.

Feb 4, 2014

STEMucator

Homework Helper

Why is a substance with an endothermic heat of solution able to dissolve?

Is it due to the activation energies being reached (forming activated complexes)? If so then I'm guessing this has to do with temperature.

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Feb 5, 2014

Borek

Mentor

Solution gets cold, but the entropy grows. After all it is ΔG that is a driving force, and ΔG = ΔH - TΔS.

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