An alkali will only exhibits show its alkaline properties
when it is dissolved in water.
Presence of water
Molecules in alkali will ionize
to hydroxide ions
An alkali wills only
exhibits show its alkaline properties when it is dissolved in water
(the
presence of hydroxide ions)
Without the presence of
water
Alkali remain in the form of
molecules
Cannot ionize to hydroxide
ions
No free moving hydroxide
ions
Example: In pure dry power state, the hydroxide ions
in barium hydroxide, Ba(OH)2 powder are arranged orderly at fixed
positions. Hence, dry barium hydroxide, Ba(OH)2 powder does not
exhibit alkaline properties. In aqueous state, barium hydroxide, Ba(OH)2
dissolves and ionizes completely to produce free mobile hydroxide ions. Hence,
barium hydroxide Ba(OH)2 solution can exhibit alkaline properties.