# What is a "salt"?

Nov 17, 2016

$\text{A salt}$ is typically a simple binary compound of a metal and a non-metal, and it is typically formed in acid base reactions.

#### Explanation:

When an acid neutralizes a base (or vice versa) it forms a $\text{salt}$, and water (typically we specify a water solvent when we speak of $\text{acid-base chemistry}$).

Consider the simplest acid-base reaction:

$N a O H \left(a q\right) + H C l \left(a q\right) \rightarrow N a C l \left(a q\right) + {H}_{2} O \left(l\right)$

Certainly, sodium chloride, unquestionably a salt (a binary compound of a metal and a non-metal), AND water have been formed as the result of neutralization of $H {O}^{-}$ and ${H}^{+}$. I write $\left(a q\right)$ beside the products and reactants, because in solution these species are ionized, e.g. $H {O}^{-}$, $C {l}^{-}$, $N {a}^{+}$ etc.

The acidium species is often represented as ${H}_{3} {O}^{+}$; this again is a representation. As fas as anyone knows this is a cluster of water molecules, with an extra ${H}^{+}$, i.e. ${H}_{5} {O}_{2}^{+}$, ${H}_{7} {O}_{3}^{+}$. If we treat it as ${H}^{+}$, or ${H}_{3} {O}^{+}$, we are able to do calculations and stoichiometry.

All (aqueous) acid base chemistry can be represented by the word equation:

$\text{Acid + base " rarr" salt + water}$