Discussion Overview
The discussion revolves around the thermicity of the acid dissociation constant and its relationship with temperature, specifically whether the reaction between a general acid and water is exothermic or endothermic. Participants explore the implications of bond breaking and forming in this context.
Discussion Character
- Debate/contested
- Technical explanation
- Conceptual clarification
Main Points Raised
- Some participants suggest that the reaction is endothermic, drawing parallels with the water auto-ionization reaction.
- Others propose that the thermicity can be determined by observing whether the acid dissociation constant (Ka) increases or decreases with temperature.
- A participant notes that the thermicity of the dilution of strong acids is noticeable, but questions whether this applies to all acids.
- One participant emphasizes the importance of considering which bonds are broken and formed during the reaction.
- Another participant corrects a previous claim about bond breaking, stating that only a single HA bond is broken and a single O-H bond is formed, leading to the conclusion that the reaction is endothermic if the bond enthalpy of HA is greater than that of O-H.
- One participant asserts that the reaction is exothermic based on a different reaction involving H+ and OH-, but later acknowledges that this was a mistake.
- Another participant expresses confidence that the reaction is always exothermic and suggests analyzing the net ionic equation for clarity.
Areas of Agreement / Disagreement
Participants do not reach a consensus on whether the reaction is exothermic or endothermic, with multiple competing views presented throughout the discussion.
Contextual Notes
There are unresolved questions regarding the dependence of the acid dissociation constant on temperature and the specific bond enthalpies involved in the reaction.