Liquid ammonia (anhydrous NH3(l)) is often used as a solvent. Like water, ammonia undergoes autoionization by the transfer of a proton:
|2NH3 NH4+ + NH2– K = 1×10-33 at -50°C|
Since ammonia is better proton acceptor than water, the ionization of acids is relatively enhanced in liquid ammonia. For example, acetic acid is a strong acid in liquid ammonia.
a) Estimate [NH4+] (mol/L) in pure (i.e. neutral) liquid ammonia at -50°C.
b) Calculate [NH4+] (mol/L) in a 6.29×10-2 M solution of acetic acid in liquid ammonia at -50°C.
c) Estimate [NH2–] (mol/L) in a 6.29×10-2 M solution of acetic acid in liquid ammonia at -50°C.