Chemistry of ice: Migration of ions and gases by directional freezing of water
Redistribution of anions and cations creates an electrical imbalance in ice grown from electrolyte solutions. Movement of acidic and basic ions in cooling solutions can permanently change the pH of frozen and unfrozen parts of the system, largely. The extent of pH change associated with freezing is...
| Main Authors: | , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2016-09-01
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| Series: | Arabian Journal of Chemistry |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S1878535211000736 |
| _version_ | 1828840101039308800 |
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| author | Umer Shafique Jamil Anwar Munawar Ali Munawar Waheed-uz Zaman Rabia Rehman Amara Dar Muhammad Salman Maria Saleem Naeema Shahid Mehwish Akram Arooj Naseer Nadia Jamil |
| author_facet | Umer Shafique Jamil Anwar Munawar Ali Munawar Waheed-uz Zaman Rabia Rehman Amara Dar Muhammad Salman Maria Saleem Naeema Shahid Mehwish Akram Arooj Naseer Nadia Jamil |
| author_sort | Umer Shafique |
| collection | DOAJ |
| description | Redistribution of anions and cations creates an electrical imbalance in ice grown from electrolyte solutions. Movement of acidic and basic ions in cooling solutions can permanently change the pH of frozen and unfrozen parts of the system, largely. The extent of pH change associated with freezing is determined by solute concentration and the extent of cooling. In the present work, redistribution of hydrogen, hydroxyl, carbonate, and bicarbonate ions was studied during directional freezing in batch aqueous systems. Controlled freezing was employed vertically as well as radially in acidic and basic solutions. In each case, the ions substantially migrated along with moving freezing front. Conductometry and pH-metry were employed to monitor the moving ions. Besides, some other experiments were carried out with molecular gases, such as oxygen, carbon dioxide, and chlorine and an azeotropic mixture like water–ethanol. Findings can be used to understand possible changes that can occur in preserving materials by freezing. |
| first_indexed | 2024-12-12T19:36:20Z |
| format | Article |
| id | doaj.art-5eeff7a3d06e4cbd9f67bc16e052a6e0 |
| institution | Directory Open Access Journal |
| issn | 1878-5352 |
| language | English |
| last_indexed | 2024-12-12T19:36:20Z |
| publishDate | 2016-09-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Arabian Journal of Chemistry |
| spelling | doaj.art-5eeff7a3d06e4cbd9f67bc16e052a6e02022-12-22T00:14:19ZengElsevierArabian Journal of Chemistry1878-53522016-09-019S1S47S5310.1016/j.arabjc.2011.02.019Chemistry of ice: Migration of ions and gases by directional freezing of waterUmer Shafique0Jamil Anwar1Munawar Ali Munawar2Waheed-uz Zaman3Rabia Rehman4Amara Dar5Muhammad Salman6Maria Saleem7Naeema Shahid8Mehwish Akram9Arooj Naseer10Nadia Jamil11Center for Undergraduate Studies, University of the Punjab, Lahore 54590, PakistanInstitute of Chemistry, University of the Punjab, Lahore 54590, PakistanInstitute of Chemistry, University of the Punjab, Lahore 54590, PakistanInstitute of Chemistry, University of the Punjab, Lahore 54590, PakistanInstitute of Chemistry, University of the Punjab, Lahore 54590, PakistanCenter for Undergraduate Studies, University of the Punjab, Lahore 54590, PakistanInstitute of Chemistry, University of the Punjab, Lahore 54590, PakistanInstitute of Chemistry, University of the Punjab, Lahore 54590, PakistanInstitute of Chemistry, University of the Punjab, Lahore 54590, PakistanInstitute of Chemistry, University of the Punjab, Lahore 54590, PakistanCenter for Undergraduate Studies, University of the Punjab, Lahore 54590, PakistanEarth and Environmental Sciences, University of the Punjab, Lahore 54590, PakistanRedistribution of anions and cations creates an electrical imbalance in ice grown from electrolyte solutions. Movement of acidic and basic ions in cooling solutions can permanently change the pH of frozen and unfrozen parts of the system, largely. The extent of pH change associated with freezing is determined by solute concentration and the extent of cooling. In the present work, redistribution of hydrogen, hydroxyl, carbonate, and bicarbonate ions was studied during directional freezing in batch aqueous systems. Controlled freezing was employed vertically as well as radially in acidic and basic solutions. In each case, the ions substantially migrated along with moving freezing front. Conductometry and pH-metry were employed to monitor the moving ions. Besides, some other experiments were carried out with molecular gases, such as oxygen, carbon dioxide, and chlorine and an azeotropic mixture like water–ethanol. Findings can be used to understand possible changes that can occur in preserving materials by freezing.http://www.sciencedirect.com/science/article/pii/S1878535211000736Acidity and basicityDirectional freezingFreezing frontIonic redistributionMigration of ions on freezing |
| spellingShingle | Umer Shafique Jamil Anwar Munawar Ali Munawar Waheed-uz Zaman Rabia Rehman Amara Dar Muhammad Salman Maria Saleem Naeema Shahid Mehwish Akram Arooj Naseer Nadia Jamil Chemistry of ice: Migration of ions and gases by directional freezing of water Arabian Journal of Chemistry Acidity and basicity Directional freezing Freezing front Ionic redistribution Migration of ions on freezing |
| title | Chemistry of ice: Migration of ions and gases by directional freezing of water |
| title_full | Chemistry of ice: Migration of ions and gases by directional freezing of water |
| title_fullStr | Chemistry of ice: Migration of ions and gases by directional freezing of water |
| title_full_unstemmed | Chemistry of ice: Migration of ions and gases by directional freezing of water |
| title_short | Chemistry of ice: Migration of ions and gases by directional freezing of water |
| title_sort | chemistry of ice migration of ions and gases by directional freezing of water |
| topic | Acidity and basicity Directional freezing Freezing front Ionic redistribution Migration of ions on freezing |
| url | http://www.sciencedirect.com/science/article/pii/S1878535211000736 |
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