Sodium hydroxide is a highly versatile substance and is a co-product of chlorine production. It is also known as caustic soda. It is represented as NaOH. It is one of the common alkalis or bases. Uses of sodium hydroxide: It is used in soap making. It is used in the pharmaceutical industry in the manufacturing of various . It is used in the paper industry to make paper. It is used in the aluminum industry to manufacture aluminum products. It is also used in detergents industry.