TY - JOUR
T1 - Solubility and standard Gibbs free energy of formation of natural imogolite at 25°c and 1 atm
AU - Wada, Shin Ichiro
AU - Kakuto, Yasuko
N1 - Funding Information:
Acknowledgments. We thank Showa Denko Co. Ltd. for providing us the synthetic gibbsite. This study was supported in part by the Grant-in-Aid for Scientific Research (#10355039) from the Ministry of Education, Science, Sports and Culture of Japan.
Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 1999/12
Y1 - 1999/12
N2 - We carried out a dissolution experiment to determine the solubility and the Gibbs free energy of formation of natural imogolite at 25°C and 1 atm. Purified gelatinous film of natural imogolite, synthetic gibbsite, and imogolite plus gibbsite were equilibrated in 1 mmol L-1 HCI solutions and Si, Al concentrations and pH were monitored during 700 d. Imogolite plus gibbsite and gibbsite systems reached an equilibrium after 120 d. The logarithmic values of the equilibrium constants of dissolution reactions were 12.10±0.01 for imogolite and 8.01±0.01 for gibbsite. The calculated Gibbs free energy of formation was -2929.19±3.28 kJ mol-1 for imogolite and -1155.11 ± 1.42 kJ mol-1 for gibbsite. These values predict that the silicic acid concentration at the imogolite-gibbsite equilibrium would be 0.120 mmol L-1.
AB - We carried out a dissolution experiment to determine the solubility and the Gibbs free energy of formation of natural imogolite at 25°C and 1 atm. Purified gelatinous film of natural imogolite, synthetic gibbsite, and imogolite plus gibbsite were equilibrated in 1 mmol L-1 HCI solutions and Si, Al concentrations and pH were monitored during 700 d. Imogolite plus gibbsite and gibbsite systems reached an equilibrium after 120 d. The logarithmic values of the equilibrium constants of dissolution reactions were 12.10±0.01 for imogolite and 8.01±0.01 for gibbsite. The calculated Gibbs free energy of formation was -2929.19±3.28 kJ mol-1 for imogolite and -1155.11 ± 1.42 kJ mol-1 for gibbsite. These values predict that the silicic acid concentration at the imogolite-gibbsite equilibrium would be 0.120 mmol L-1.
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U2 - 10.1080/00380768.1999.10414344
DO - 10.1080/00380768.1999.10414344
M3 - Article
AN - SCOPUS:0033385572
VL - 45
SP - 947
EP - 953
JO - Soil Science and Plant Nutrition
JF - Soil Science and Plant Nutrition
SN - 0038-0768
IS - 4
ER -