Is there a force between a particle of ionic compound?

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Discussion Overview

The discussion centers around the existence of forces between particles of ionic compounds, specifically using salt as an example. Participants explore the nature of these forces, the conditions under which they may occur, and the implications for both theoretical and practical contexts.

Discussion Character

  • Debate/contested
  • Conceptual clarification
  • Technical explanation

Main Points Raised

  • One participant questions the concept of a "particle of an ionic compound," suggesting that such a term is not applicable except in specific scenarios like NaCl in gas phase or ion pairs in low polarity solvents.
  • Another participant argues that particles of ionic compounds do exist, referring to them as "dust" and noting that salt crystals can form and exist in the environment. They describe how charge separation in these particles can create electric dipoles and suggest that attractive forces exist between them, but only at very close distances.
  • A different viewpoint discusses the behavior of silver chloride crystals during titration, explaining that the presence of excess chloride ions can lead to repulsion between crystals due to negative charges, which affects their stability and interaction.
  • One participant acknowledges a misunderstanding regarding the term "particle," clarifying that it can also mean "molecule" in another language, which may have influenced their interpretation of the original question.

Areas of Agreement / Disagreement

Participants express differing views on the definition and existence of particles in ionic compounds, with some asserting their existence and others questioning the terminology. The discussion remains unresolved with multiple competing perspectives on the nature of forces between these particles.

Contextual Notes

There are nuances in the definitions of "particle" and "molecule," which may affect interpretations of the discussion. Additionally, the strength and relevance of forces between particles are described as highly dependent on distance and specific conditions.

kevin_tee
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Is there a force between a particle of ionic compound? (such as salt) (image that I uploaded), I know that there are intermolecular force between atoms, molecules, ions but how about ionic compound? Thank you.
 

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Technically there is no such thing as a "particle of an ionic compound", unless you are talking about some exotic situations (say, NaCl in gas phase, or ion pairs in low polarity solvents).
 
Borek is wrong, to the point of ridiculousosity. (yeah, I made that word up) Of course there are particles of ionic, as well as covalent compounds. One term for it is "dust". Anyone living by the ocean is aware that salt spray can deposit fine particles (crystals) of salt. (Which is another, more common, term for them).(Not saying they're pure or anything.)
The crystals or particles themselves will be almost electrically neutral...I say "almost" because friction and particle impacts can dislodge electrons (temporarily) and create charge (so can ionizing radiation, if you want a stretch). But let's ignore that effect.
So, what we have is a material composed of positive charge centers and negative charge centers (anions and cations). Any charge separation creates what we call an electric dipole, which is an electric field. Cut to the chase and the charge separation will on average create an attractive force between particles, BUT the strength of this force is miniscule for any particle that you can see. That is, its only important for distances on the order of the size of small molecules. So, yeah you can have attractive forces, but unless the two surfaces are very close together, the + and - charges interior to them 'average out' and result in virtually no net force. IOW yes but only if the two particles are very very close to one another. Look up Intermolecular Forces, London Forces, or Dispersion Forces on wikipedia. (but note that those explanations tend to ignore the effect between ionic crystals, you have to read in between the lines.)
There's lots that's been written with regard to the formation of the Solar System and the tendency of small particles to form large particles, the dipole forces are one of the considerations in building models of how the Solar System developed. It has lots of other applications, too.
 
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If you ever did a titration of, say, chloride with silver nitrate solution, you know that the silver chloride crystalites remain in suspension until the equivalent point is reached when suddenly all AgCl falls out. The reason is that superfluous chloride ions remain absorbed to the crystals charging them up negatively so that they repell each other.
This is also how colloids are stabilized.
However, if the crystals are neutral in sum, there are only weak forces between the crystals, as most of the multipole moments of an arrangement of many positive and negative charges vanish which leads to a rapid decrease (with a high negative power of distance) of forces between crystals.
 
Sorry, my mistake. "Particle" translates to Polish "cząsteczka" which means both "particle" and "molecule". Somehow I read the question as referring to "molecules".
 

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