The
overall reaction, diagramed at the right, represents a competition
between an ammonia molecule and a hydroxide ion for the proton:
NH3
+ H2O
<====> NH4+
+ OH-
The double arrow indicates that the actual process is not all-or-nothing,
but is a competition or balance between the forward and reverse steps.
A substance that produces hydroxide ions in water solution is called
a base. Lithium hydroxide, LiOH, is a base because it dissociates
in water into lithium ions and hydroxide ions:
