# Consider this reaction: acid base + salt water. What type of reaction is this?

Sep 2, 2017

This is a $\text{neutralization reaction......}$

#### Explanation:

And this represents the reaction that acids and bases undergo in water......

An acid is a species that increases concentrations of the characteristic cation of water, i.e. ${H}_{3} {O}^{+}$, $\text{the hydronium ion}$; this is a conceptual species, which as far as we know is a cluster of water molecules WITH an EXTRA proton associated; i.e. ${H}_{5} {O}_{2}^{+}$ or ${H}_{7} {O}_{3}^{+}$; we REPRESENT this acidium species as ${H}^{+}$ or more commonly ${H}_{3} {O}^{+}$.

And a base is species that increases concentrations of the characteristic anion of water, i.e. $H {O}^{-}$; and we conceive of this as a water molecule LESS a proton.

In water we know that the concentrations of hydronium and hydroxide ions are governed by the equilibrium:

$2 {H}_{2} O \left(l\right) r i g h t \le f t h a r p \infty n s {H}_{3} {O}^{+} + H {O}^{-}$, where at $298 \cdot K$ we have the equilibrium.....$\left[{H}_{3} {O}^{+}\right] \left[H {O}^{-}\right] = {10}^{-} 14$.

And so we can write concrete examples of the given equilibrium....

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

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