The borax is a salt of strong base with its chemical formula Na2[B4O5(OH)4].8H2O. The borax is basic because a strong base is added in weak acid. Therefore, resultant aqueous solution of borax is basic in nature. The reaction corresponding to the solution of borax in water is given as, Na2B4O7+7H2O→2NaOH+4H3BO3