# What is the formula for hydrochloric acid? What are the symbols with oxidation numbers?

Nov 30, 2016

Gaseous hydrogen chloride is represented as $H C l \left(g\right)$......

#### Explanation:

In water, hydrogen chloride dissolves and ionizes to form aqueous hydrogen chloride:

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

Oxidation number results from distribution of the charge to the most electronegative atom; here, we get $H \left(+ I\right)$ and $C l \left(- I\right)$.

When we write ${H}_{3} {O}^{+}$, the $\text{hydronium ion}$, this is more of a convenience than an actual entity. When we write ${H}^{+}$ or ${H}_{3} {O}^{+}$ we mean the $\text{acidium}$ species in water, a cluster or 3 or 4 water molecules WITH an EXTRA ${H}^{+}$, i.e. ${H}_{7} {O}_{3}^{+}$ or ${H}_{9} {O}_{4}^{+}$. The extra proton rapidly exhanges between clusters, and ${H}_{3} {O}^{+}$ is a convenient representation.