Question

all alkalis are bases but all bases are not alkalis comment and write examples of both

Answer 1

Only alkalis and not all bases dissolve in water to give OH- ions .
Examples of alkali are NaOH, KOH, et cetera. Thus the set of alkalis is smaller than that of bases, simply because it is a subset of the set base.
Hence, all alkalis are bases, but all bases are not alkalies.

Answer 2

bases are substance which reacts acid to form salt and water such bases are called alkalis. for example sodium hydroxide and sulphur dioxide are with bases but they are not soluble with water. hence all alkalis are bases but all bases are not alkalize.