Pulse Radiolysis Studies in Lanthanide Aqueous Solutions. II. Formation, Spectrum, and Some Chemical Properties of Praseodymium(IV) in Aqueous Solution

1972 ◽  
Vol 56 (7) ◽  
pp. 3294-3297 ◽  
Author(s):  
M. Faraggi ◽  
A. Feder
1974 ◽  
Vol 29 (1-2) ◽  
pp. 86-88b ◽  
Author(s):  
Burkhard O. Wagner ◽  
Herbert Klever ◽  
Dietrich Schulte-Frohlinde

To study the reaction of the solvated electron with 5-bromouracil an aqueous solution has been examined by conductometric pulse radiolysis at pH values between 4.68 and 8.74. Alcohol was added to scavenge the hydrogen atom and the hydroxyl radical. G(Br—) = (2.64 ± 0.08)/100 eV was found to be independent of the pH. The mobility of the bromouracil mono-anion was measured to be (2.7 ± 0.2) 10-4 cm2 V-1 s-1 at 20°C, and the rate constant of reaction (3b) was determined to be k(H+ BrUr-) = (2.3 ± 0.2) 1010 I mole-1 s-1*.


RSC Advances ◽  
2017 ◽  
Vol 7 (87) ◽  
pp. 54969-54979 ◽  
Author(s):  
Dezhi Chen ◽  
Shasha Xie ◽  
Caiqin Chen ◽  
Hongying Quan ◽  
Li Hua ◽  
...  

In recent years, the application of biochar to remove contaminants from aqueous solutions has become interesting due to favorable physical/chemical properties and abundant feedstocks.


1970 ◽  
Vol 48 (2) ◽  
pp. 393-394 ◽  
Author(s):  
W. A. Seddon ◽  
M. J. Young

Pulse radiolysis of aqueous solutions of nitric oxide at neutral pH shows that the reaction initiated by the hydrated electron, e−(aq), proceeds via NO− and a new transient thought to be (N2O2)−, and not HNO as indicated previously by steady state radiolysis.


Pulse radiolysis supplemented by steady state radiolysis of aqueous solutions containing some of the following solutes: N 2 O, Br - , BrO - , BrO - 2 , BrO - 3 , CO 2- 3 , and OH - has been used to identify the absorption spectra of BrO ( λ max = 350 nm) and BrO 2 ( λ max = 475 nm) and to evaluate the following rate constants (units, M -1 s -1 ): e - aq. + BrO - → Br - + O - (2.3 ± 0.5 x 10 10 ); e - aq. + BrO - 2 → BrO + O 2- (1.8 ± 0.2 x 10 10 ); e - aq. + BrO - 3 → BrO 2 + O 2- (4.1 ± 0.2 x 10 9 ); OH + BrO - → OH - + BrO (4.5 x 10 9 ); O - + BrO - → BrO + O 2- (4.6 x 10 9 ); OH + BrO - 2 → OH - + BrO 2 (1.9 x 10 9 ); Br - 2 + BrO - → BrO + 2Br - (8.0 ± 0.7 x 10 7 ); Br - 2 + BrO - 2 → BrO + Br - + BrO - (8.0 ± 0.8 x 10 7 ); BrO + BrO - 2 → BrO - + BrO 2 (3.4 ± 0.7 x 10 8 ); 2BrO 2 ⇌ Br 2 O 4 ( k = 1.4 x 10 9 and K = 19 M -1 ); Br 2 O 4 + OH - → H + + BrO - 2 + BrO - 3 (7 x 10 8 ); 2BrO + H 2 O → BrO - + BrO - 2 + 2H + (4.9 ± 1.0 x10 9 ); CO - 3 + BrO - → CO 2- 3 + BrO (4.3 ± 0.4 x 10 7 ); CO - 3 + BrO - 2 → CO 2- 3 + BrO 2 (1.1 ± 0.1 x 10 8 ). In contrast to their chlorine analogues, little is known of the chemistry of the bromine oxides in aqueous solution. In this paper we describe the methods of formation and identification of the radicals BrO and BrO 2 , and their reactions with various oxybromine species, as elucidated by the techniques of pulse radiolysis and kinetic spectroscopy applied to aqueous solutions containing oxybromine anions.


1997 ◽  
Vol 94 ◽  
pp. 244-250 ◽  
Author(s):  
I Janik ◽  
P Kujawa ◽  
P Ulanski ◽  
JM Rosiak

2018 ◽  
Vol 69 (9) ◽  
pp. 2323-2330 ◽  
Author(s):  
Daniela C. Culita ◽  
Claudia Maria Simonescu ◽  
Rodica Elena Patescu ◽  
Nicolae Stanica

A series of three chitosan-based magnetic composites was prepared through a simple coprecipitation method. It was investigated the influence of mass ratio between chitosan and magnetite on the physical and chemical properties of the composites in order to establish the optimum conditions for obtaining a composite with good adsorption capacity for Pb(II) and Cu(II) from mono and bicomponent aqueous solutions. It was found that the microspheres prepared using mass ratio chitosan / magnetite 1.25/1, having a saturation magnetization of 15 emu g--1, are the best to be used as adsorbent for the metal ions. The influence of different parameters such as initial pH values, contact time, initial concentration of metal ions, on the adsorption of Pb(II) and Cu(II) onto the chitosan-based magnetic adsorbent was investigated in details. The adsorption process fits the pseudo-second-order kinetic model in both mono and bicomponent systems, and the maximum adsorption capacities calculated on the basis of the Langmuir model were 79.4 mg g--1 for Pb(II) and 48.5 mg g--1 for Cu(II) in monocomponent systems, while in bicomponent systems were 88.3 and 49.5 mg g--1, respectively. The results revealed that the as prepared chitosan-based magnetic adsorbent can be an effective and promising adsorbent for Pb(II) and Cu(II) from mono and bicomponent aqueous solutions.


1984 ◽  
Vol 49 (3) ◽  
pp. 559-569 ◽  
Author(s):  
Jaroslav Nývlt

The metastable zone width of an aqueous solution of KCI was measured as a function of the time and temperature of overheating above the equilibrium solubility temperature. It has been found that when the experiments follow close upon one another, the parameters of the preceding experiment affect the results of the experiment to follow.The results are interpreted in terms of hypotheses advanced in the literature to account for the effect of thermal history of solution. The plausibility and applicability of these hypotheses are assessed for the given cause of aqueous solution of a well soluble electrolyte.


1879 ◽  
Vol 29 (196-199) ◽  
pp. 472-482 ◽  

In order to investigate this subject, I devised and constructed the following apparatus :—A and B are two thin glass basins, 81 millims. internal diameter (= 5,153 sq. millims. of mercury surface), and 6·0 centims. deep; each containing a layer of mercury about 1·0 centim. deep, covered by a layer, about 3 centims. deep, of the aqueous solution to be examined.


2021 ◽  
Author(s):  
Junyi Li ◽  
Zoltán Szabó ◽  
Mats Jonsson

Four different uranyl-(peroxide)-carbonate complexes were identified during studtite and meta-studtite dissolution in aqueous solution containing 10 mM HCO3− by 13C NMR.


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