LXXXV.—Heats of neutralisation of acids and bases in dilute aqueous solution

The Schiff base, N-n-butylsalicylideneimine, extracts more than 99.8% beryllium into toluene from dilute aqueous solution. The distribution of beryllium has been studied in the pH range 5-13 and is discussed in terms of the several complex equilibria in aqueous solution. The stability constants of the complexes formed between beryllium and the Schiff base are log β1 11.1 and log β2 20.4, and the distribution coefficient of the bis complex is 550. Over most of the pH range, hydrolysis of the Be2+ ion competes with complex formation and provides a means of measuring the hydrolysis constants. They are for the reactions: Be(H2O)42+ ↔ 2H+ + Be(H2O)2(OH)2, log*β2 - 13.65; Be(H2O)42+ ↔ 3H+ + Be(H2O)(OH)3-, log*β3 -24.11.

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Determination of the complexation properties of a crosslinked poly(acrylic acid) gel with copper(II), nickel(II), and lead(II) in dilute aqueous solution

Canadian Journal of Chemistry ◽

10.1139/v01-059 ◽

2001 ◽

Vol 79 (4) ◽

pp. 370-376 ◽

Cited By ~ 5

Author(s):

Catherine Morlay ◽

Yolande Mouginot ◽

Monique Cromer ◽

Olivier Vittori

Keyword(s):

Aqueous Solution ◽

Ionic Strength ◽

Acrylic Acid ◽

Metal Ion ◽

Conditional Stability ◽

Binding Properties ◽

Complex Species ◽

Complexing Capacity ◽

Dilute Aqueous Solution ◽

Poly Acrylic Acid

The possible removal of copper(II), nickel(II), or lead(II) by an insoluble crosslinked poly(acrylic acid) was investigated in dilute aqueous solution. The binding properties of the polymer were examined at pH = 6.0 or 4.0 with an ionic strength of the medium µ = 0.1 or 1.0 M (NaNO3) using differential pulse polarography as an investigation means. The highest complexing capacity of the polyacid was obtained with lead(II) at pH = 6.0 with µ = 0.1 M, 4.8 mmol Pb(II)/g polymer. The conditional stability constants of the complex species formed were determined using the method proposed by Ruzic assuming that only the 1:1 complex species was formed; for lead(II) at pH = 6.0 and µ = 0.1 M, log K' = 5.3 ± 0.2. It appeared that the binding properties of the polymer increased, depending on the metal ion, in the following order: Ni(II) < Cu(II) < Pb(II). The complexing capacity and log K' values decreased with the pH or with an increase of the ionic strength. These results were in agreement with the conclusions of our previous studies of the hydrosoluble linear analogues. Finally, with the insoluble polymer, the log K' values were comparable to those previously obtained with the linear analogue whereas the complexing capacity values expressed in mmol g-1 were slightly lower.Key words: insoluble crosslinked poly(acrylic acid), copper(II), nickel(II), and lead(II) complexation.

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Quantum yields for reaction of pollutants in dilute aqueous solution

Environmental Science & Technology ◽

10.1021/es60139a010 ◽

1978 ◽

Vol 12 (3) ◽

pp. 327-329 ◽

Cited By ~ 112

Author(s):

Richard G. Zepp

Keyword(s):

Aqueous Solution ◽

Quantum Yields ◽

Dilute Aqueous Solution

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Effects of Aging on the Solubility of Palladium

MRS Proceedings ◽

10.1557/proc-412-881 ◽

1995 ◽

Vol 412 ◽

Cited By ~ 4

Author(s):

C. Oda ◽

H. Yoshikawa ◽

M. Yui

Keyword(s):

Aqueous Solution ◽

Aging Time ◽

Room Temperature ◽

High Level Waste ◽

Anaerobic Conditions ◽

Dilute Aqueous Solution ◽

Waste Repository ◽

Ph Range ◽

Effects Of Aging ◽

High Level

AbstractPalladium solubility was measured in a dilute aqueous solution at room temperature in the pH range from 3 to 13 under anaerobic conditions. Crystalline Pd metal was clearly visible and the concentration of palladium in solution decreased gradually with aging time. The palladium concentrations in solution were less than 9.4×10-10M in the pH range from 4 to 10 and increased to 10-7M in the pH range greater than 10. This study suggests that palladium concentrations in certain high-level waste repository environments may be limited by Pd metal and may be less than 10-9M.

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