Heat of Reaction Experiment, High school level

AI Thread Summary
The discussion centers on an experiment involving the reaction between hydrochloric acid (HCl) and sodium hydroxide (NaOH), which is exothermic despite the initial energy absorption during dissociation. The key point is that while Na+ and OH- ions require energy to dissociate, the subsequent formation of water releases more energy than was absorbed, resulting in a net release of heat. The reorganization of ions into a more stable water molecule contributes to this energy release, leading to an observable increase in temperature. The explanation highlights that the stability of the resulting water is greater than that of the separate ions, making the overall reaction exothermic. Understanding this energy balance is crucial for grasping the thermodynamics of acid-base reactions.
bethanyd
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Homework Statement
I am working on a correspondence grade 12 Chemistry Course and I am confused by one question. I did an experiment involving hydrochloric acid (HCl) and sodium hydroxide (NaOH). Here is the question:
"In a reaction, Na+ ions are separated from OH- ions, a process of dissociation that absorbs energy, yet, in the end, heat was liberated by the overall process. Explain."

This has been asked before on this forum but there was not really a clear answer posted so I thought perhaps we could discuss it again. Here is the archived thread: https://www.physicsforums.com/archive/index.php/t-77030.html

The attempt at a solution
So I understand that, since the reaction was exothermic, something other than the breaking of the NaOH bonds must have occurred which took less energy and thus released the excess energy in the form of heat. I do not quite understand what happened that would have taken so much less energy. Would the following be a correct and reasonable answer: "The reorganization and formation of water took much less energy and resulted in heat being released." ?
 
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The solvated proton from the acid and the solvated hydroxide from the base are less stable (and have the potential to react...) than the water which results from their combining. The water is more stable than the separate ions. Energy is released into the environment upon this neutralization, and the increase in temperature can be observed (and measured).
 
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