# Are H_3O^+ or H^+ actual species?

Nov 16, 2017

Well it can represent one.....

#### Explanation:

When an acid dissolves in a solvent it is conceived to increase the concentration of the CHARACTERISTIC CATION solvent of the solvent. And we commonly use water as a solvent....and so should we dissolve $H X$ in water, protonolysis of the solvent is conceived to occur......to give the hydronium ion.

$H X \left(g\right) + {H}_{2} O \left(l\right) \rightarrow {\underbrace{{H}_{3} {O}^{+}}}_{\text{hydronium ion}} + {X}^{-}$

or more simply we designate the acid principle as $\text{protium ion} :$

$H X \left(g\right) \stackrel{{H}_{2} O}{\rightarrow} {\underbrace{{H}^{+}}}_{\text{protium ion}} + {X}^{-}$

And note that this is a conception rather than an actuality, the actual acid species, is probably ${H}_{9} {O}_{4}^{+}$; a cluster of 3-4 water molecules WITH an EXTRA PROTON, that passes rapidly, tunnels if you like from cluster to cluster. We use ${H}_{3} {O}^{+}$ or ${H}^{+}$ interchangeably to represent this species in solution.

$H X \left(g\right) + {H}_{2} O \left(l\right) r i g h t \le f t h a r p \infty n s {\underbrace{{H}_{3} {O}^{+}}}_{\text{hydronium ion}} + {X}^{-}$

The strength of the acid is defined by the completeness of the equilibrium. For strong mineral acids, ${H}_{2} S {O}_{4}$, $H C l {O}_{4}$, $H X$, $\left(X \ne F\right)$, the equilibrium LIES to the right as we face the page.

For weaker acids, $H O A c$, $H F$, $N {H}_{4}^{+}$, the equilibrium lies to the left as written.....