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This question already has an answer here:

I am a high school student and I was reading a textbook and it gave me the equation of this hydrochloric acid which was put into water and the products formed were hydronium and chlorine.

$\ce{HCl + H2O -> H3O+ + Cl-}$

I understand that $\ce{HCl}$ (Hydrochloric acid) breaks up in the water to become 2 free ions (Hydrogen & Chlorine) and the Hydrogen bonds to the water because of electronegativity that causes the oxygen to be partially charged and so the $\ce{H+}$ will bond to water giving us $\ce{H3O+}$. This makes sense to me however I do not quite understand why $\ce{Cl-}$ is left "alone".

If there is a lot of water with only little amount of acid added surely it should lead to the $\ce{Cl-}$ also bonding to water or hydronium? Why does it not bond to them?

My Hypothesis

I have attempted to use my knowledge of physics and chemistry to tackle this problem, I am not as well-versed in chemistry so please bare with my "beginners" attempt at understanding this.

Water ($\ce{H2O}$) is a polar molecule due to electronegativity so perhaps as the chlorine is trying to attach to the hydrogen part of the molecule the oxygen's negative field is slightly stronger than the attractive forces of the hydrogen in the molecule of water thus the chlorine cannot bond with the water.

Next hydrogen is covalently bonded to water so their outer orbitals are filled up so there is no need for the chlorine to even bond as the hydrogen has filled its orbitals.

Please criticize my thinking as it will only improve my scientific curiosity and intuition.

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marked as duplicate by bon, Klaus-Dieter Warzecha, M.A.R., user15489, ron Jul 31 '15 at 12:28

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    $\begingroup$ Welcome to Chemistry.SE! I see you have figured out some of our MathJax formatting, but if you wrap your chemistry in a \ce{...}, you get even prettier formatting! For example, $\ce{H3O+}$ comes out as $\ce{H3O+}$ and not $H_3O^+$. Here is a link to our help center page on MathJax (which links to a meta post with more information): chemistry.stackexchange.com/help/notation. $\endgroup$ – Ben Norris Jul 30 '15 at 19:28
  • $\begingroup$ We also discourage using Mathjax in question titles because it makes them hard to search, both here and using external search engines. I edited your question to clean up the Mathjax this time, and to choose perhaps a better tag (acid-base). $\endgroup$ – Ben Norris Jul 30 '15 at 19:29
  • $\begingroup$ Actually @ron beat me to it! $\endgroup$ – Ben Norris Jul 30 '15 at 19:30
  • $\begingroup$ Looks like just another dupe of this and this. $\endgroup$ – Wildcat Jul 30 '15 at 19:39
  • $\begingroup$ @Wildcat It's about chloride not hydrogen ions. $\endgroup$ – bon Jul 30 '15 at 20:12

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