Sodium hydroxide is used in the manufacture of soap. It is used in petroleum refining; in making medicines, paper, pulp, etc. It is used in making rayon.
Calcium hydroxide is also known as slaked lime. It is used to neutralize acid in water supplies; in the manufacture of bleaching powder; as a dressing material for acid burns; as an antidote for food poisoning.
Ammonium hydroxide is used to remove ink spots from clothes and to remove grease from window-panes. It is used in the cosmetic industry.
Alkalis are used in alkaline batteries. Generally, potassium hydroxide is used in such batteries.
Strontium hydroxide(Sr(OH)2) is used in the food industry for the refining of beet sugar.