# Why do H+ ions not react with the atoms/molecules they're originally bonded to?

## Main Question or Discussion Point

If you dissolve HCl in solution, the why do the H+ and the Cl- not react with one another? The H+ will react with any metal, will react with OH-, will react with your skin for sure, along with many other things, but why does it seem to just ignore a perfectly good negative ion that is in the exact same concentration as it is.

But it DOES. You have to remember this is hydrogen chloride gas IN solution, which allows Dissociation of the HCl molecule due to Hydration.

movies
Yeah, better to think of it as the HCl molecule reacts with water to dissociate the two.

Borek
Mentor
Hydrogen chloride dissociates in water

$$HCl \leftrightarrow H^+ + Cl^-$$

dissociation constant for this reaction is

$$K_a = \frac {[H^+][Cl^-]} {[HCl]}$$

pKa = -4 (see pKa tables at ChemBuddy).

So in every solution of hydrochloric acid you may expect minute amounts of undissociated HCl - but as the Ka constant is large, these will be VERY minute.