NOPR Collection:

The history of bromine from discovery to commodity

Wed, 01 May 2002 00:00:00 GMT

Title: The history of bromine from discovery to commodity Authors: Wisniak, Jaime Abstract: The discovery of bromine represents one of the first experimental evidences that elements could be grouped in families of similar properties. Transformation of the new element and its derivatives into a commercial reality had to wait until automobiles begun to be mass-produced. The pattern end use of bromine has reflected the changes in social appreciation of environmental protection and safety. From a strong initial use as gasoline additive and agricultural chemical, the end uses are changing drastically into flame-retardants and sanitary uses. From a strictly initial European industrial activity it has turned into an important chemical activity for the United States, Jordan, and Israel. Page(s): 263-271

An efficient route for the synthesis of chloroaceticanhydride and benzyl mercaptan

Wed, 01 May 2002 00:00:00 GMT

Title: An efficient route for the synthesis of chloroaceticanhydride and benzyl mercaptan Authors: Jagadish, R L; Vijayakumar, T R; Rai, K M Lokanatha Abstract: An efficient and cost saving procedure for the synthesis of chloroacetic anhydride and benzyl mercaptan is discussed here. Page(s): 261-262

Ion-exchange kinetics on styrene supported zirconium(IV) tungstophosphate: An organic-inorganic type cation exchanger

Wed, 01 May 2002 00:00:00 GMT

Title: Ion-exchange kinetics on styrene supported zirconium(IV) tungstophosphate: An organic-inorganic type cation exchanger Authors: Khan, A A; Niwas, R; Alam, M M Abstract: Kinetics of exchange reaction of Mg²⁺, Ca²⁺, Sr²⁺, Ba²⁺, Cu²⁺, Mn²⁺, Ni²⁺ and Zn²⁺ on styrene supported zirconium (IV) tungstophosphate cation exchanger has been studied at 25, 33, 50 and 65^oC. The rate of exchange is found to be particle diffusion controlled at a metal ion concentration 0.02 M in aqueous medium. Various kinetic parameters such as self-diffusion coefficient, D₀, energy of activation, E_ᴂand entropy of activation, ΔS*, have been calculated. Page(s): 256-260

The phosphine oxides Cyanex-921, Cyanex-923 and Cyanex-925 as extractants for Pb(II) from aqueous media

Wed, 01 May 2002 00:00:00 GMT

Title: The phosphine oxides Cyanex-921, Cyanex-923 and Cyanex-925 as extractants for Pb(II) from aqueous media Authors: Iyer, J N; Pawar, S D; Dhadke, P M Abstract: The behaviour of neutral phosphine oxides Cyanex-921, Cyanex-923 and Cyanex-925 in the extraction of Pb(II) from nitrate media is described. The extraction of Pb(II) was found to be quantitative in the pH range 8.0-9.0 with these extractants. From the metal loaded organic phases for these extractants, Pb(II) was stripped back with 0.5 M H₂SO₄. The effects of pH, temperature, equilibrium time, diluents, diverse ions and stripping ability using various acids on the extraction of Pb(II) have been studied. The methods are also extended for the analysis of real samples. Page(s): 251-255