# What is the physical state of pure hydrogen chloride?

Jul 12, 2017

Pure $H C l$ is a room temperature gas......

#### Explanation:

.......and it can be supplied in metal cylinders.....

And if you bubble the gas thru water, you get hydrochloric acid.....

$H C l \left(g\right) + {H}_{2} O \left(l\right) \rightarrow {H}_{3} {O}^{+} + C {l}^{-}$

.....equivalently......

$H C l \left(a q\right) \rightarrow {H}^{+} + C {l}^{-}$

The point is that $H C l \left(g\right)$ is mighty soluble in water, to the tune of approx. $10.6 \cdot m o l \cdot {L}^{-} 1$ - this is conc. hydrochloric acid......this is the reagent they supply in bottles......

The hydronium ion, ${H}_{3} {O}^{+}$, is a conception not an actuality. As far as anyone knows, the actual species is a cluster of 3-4 water molecules with an EXTRA proton, i.e. ${H}_{7} {O}_{3}^{+}$, or ${H}_{9} {O}_{4}^{+}$ - this is what we mean when we write $H C l \left(a q\right)$.......we write, without loss of generality, ${H}_{3} {O}^{+}$ or even as ${H}^{+}$.

I have said much the same thing here.