1,10-Phenanthroline CAS NO.66-71-7

White (transparent) crystalline solid, very slightly soluble in water (0.3% in cold water and 2% in boiling water) . Soluble in alcohol and hot ben…

White (transparent) crystalline solid, very slightly soluble in water (0.3% in cold water and 2% in boiling water) . Soluble in alcohol and hot benzene. Dissolves in dilute acids (HCl or H2SO4) to form clear solutions of the corresponding salt of the base. Aqueous or alcoholic solutions of the base give an intense red colour with ferrous salts due to the formation of the Fe++ complex 'ferroin'. Uses 1. Estimation of iron. 2. The Ferrous iron complex, ferrion is a valuable Oxidation-Reduction indicator. 3. Estimation of borate in effluents. Preparation of Ferroin Fe (C12H8N2)3++ SO4 - - Dissolve 0.56gm of AR Ferrous Sulphate (FeSO4, 7H2O) or equivalent amount of Ferrous Ammonium Sulphate (0.79g) in 50ml water. Add 1.2g of 1, 10 - Phenanthroline monohydrate and stir until dissolved. The resulting deep red solution is diluted to 100ml with water. One drop of the indicator is sufficient for titration. Colour is deep red in reducing media and pale blue (nearly colourless when dilute) in oxidising media.