# Why is ammonia not an arrhenius base?

May 27, 2018

Well, Arrhenius bases are conceived to be sources of the hydroxide ion in aqueous solution...

#### Explanation:

And since ammonia does NOT contain hydroxide ions, i.e. its chemical formula is $N {H}_{3}$, it does not fall under the Arrhenius' umbrella. We classify ammonia as a Bronsted-Lowry base...and its conjugate acid is ammonium ion, $N {H}_{4}^{+}$...

$N {H}_{3} \left(a q\right) + {H}_{2} O \left(l\right) r i g h t \le f t h a r p \infty n s N {H}_{4}^{+} + H {O}^{-}$

${K}_{b} = 1.80 \times {10}^{-} 5$

Note that this is all conceived to occur in AQUEOUS solution, i.e. in a water solvent. In liquid ammonia solvent, and use of this solvent is nowadays fairly standard and straightforward....the following acid-base regime obtains...

$2 N {H}_{3} \left(l\right) r i g h t \le f t h a r p \infty n s {\underbrace{N {H}_{2}^{-}}}_{\text{the amide ion}} + N {H}_{4}^{+}$

Ammonia has a normal boiling point of $33.3$ ""^@C...
The degree of dissociation can be measured, but I don't my text at hand right now....