JOURNAL of the Tunisian Chemical Society

serving the Research, the Education and the Industry

Synthèse de monoacides α-amines N-alkyles et N,N-dialkyles par monocondensation du chlorhydrate de sodium sur des amines primaires et secondaires

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The study of sodium chloracetate monocondensation on certain primary and secondary amines with hydrocarbonus chains which are either linear or ramified or cyclic, has enabled us to synthesize nine α-aminoacids. We have purified those α-aminoacids by preparing their chlorhydrates.

F. M'henni, Z. Mighri

Pages 3-12

Etude par spectroscopie infra-rouge de l'adsorption d'oxygène sur γFe2O3 : Interaction avec H2, H2O et CH2=CH-CH3

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The reaction of oxygen with the surface of γFe2O3 has been studied by infrared spectroscopy method. It has been shown that a variety of forms of adsorbed oxygen is produced. The adsorption bands corresponding to the different forms of adsorbed oxygen lie in the 1600 - 800 cm-1 spectral range. Two species are clearly distinguished: one neutral molecular specie highly polarised which absorbs in the 1500-1540 cm-1 region and one charged specie O2n- with 0 < n < 1 which absorbs in the 1500 - 1200 cm-1 region. Their thermodesorption in vacum at 250°C is accompanied by sample reduction to Fe3O4 state. Hydrogen reacts selectively (according to temperature) with adsorbed molecular oxygen then lattice oxygen. With molecule interacts physically among hydrogen bonds with some O2n- species, however dipole-dipole interaction with polarized species is pointed out. At room temperature, propen adsorption leads to chemisorbed species obtained by a reaction with adsorbed oxygen.

H. Batis

Pages 13- 23

Etude de la fixation du magnésium d'un milieu phosphorique sur résines échangeuses d'ions

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The fixation of magnesium in phosphoric acid medium is studied on different types of cation exchange resins. On account of its high exchange capacity, the sulfonic resin Duolite C 20 is kept to check the factors (pH and metal concentration) governing the exchange phenomenon. After determination of the exchange constant the square diagram representative of the equilibria between phases is traced.

M. Feki, M. Chaabouni, H.F. Ayedi

Pages 25-35

Application de technique d'intégration numérique a la conception rationnelle de réacteurs. Réacteur électrochimique à électrode volumique

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For reactor design, many different balances (material, energy...) take place and require analytical or numerical techniques. In this study, an approach to the understanding of an electrochemical reactor is developed similar to that considered for the case of a chemical reactor. Both mass transfer and current density equations connecting the different species in solution, form a system of three differential equations. The numerical resolution is proposed in two examples:

  1. The copper recovery in sulfuric acid medium with a axial field reactor working in diffusion kinetic.
  2. The electrodissolution of iron in water with a radial field reactor working in activation kinetic.

M. Benzina, A. Ratel, A. Bellagi, G. Lacoste

Pages 37-50

Short communication: Sur la réaction de dissolution des phosphates dans les acides: I. Dispositif expérimental et premiers essais

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An isoperibol calorimeter is described ; and the device has been tested with the dissolution of [Tri (methyl hydroxy) amino methane] in HCl 0,1 M/Kg solution. Test reaction gave ΔH = 30,07 KJ mol. The results obtained with this device for the βT.C.P. dissolution in HNO3 55 Wt % lead to ΔH = -154,89 ± 0,33 KJ.mol.

A. Ben Cherifa, B. Omezzine, M. Jemal

Pages 53-55

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