what are bases ?

Any class of compounds that form hydroxyl ions (OH) when dissolved in water is called Base. 

 Its aqueous solutions react with acids to form salts. 

 Bases turn red litmus paper blue and have a pH greater than 7.

 Some of the common bases are NH₄OH, NaOH, KOH.

Bases are Bitter in taste.

Bases are Odorless (except ammonia).

Bases are slippery.

Bases reacts with fats and oils.

Bases gives pink color with phenolphthalein