# Why do ammonium salts give solutions whose pH<7?

Aug 13, 2017

The ammonium chloride salt undergoes ionization in water......

#### Explanation:

$N {H}_{4} C l \left(s\right) \stackrel{{H}_{2} O}{\rightarrow} N {H}_{4}^{+} + C {l}^{-}$

The ammonium ion also acts as a weak acid in water to give equilibrium quantities of ammonia, $N {H}_{3} \left(a q\right)$ and the hydronium ion, ${H}_{3} {O}^{+}$....

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

The equilibrium lies to the LEFT as written, but it does operate. $p {K}_{a} = 9.25$ for ammonium ion.