• 主题
高级搜索  >
历史搜索 清空历史
首页> 美国政府科技报告 >Amphoteric Oxide Hydrates, Their Aqueous Solutions and Their Crystallizing Compounds. Part XIII. Silicates and Dissolved Silicon Dioxide Hydrate in Basic and Acidic Solutions
【24h】

Amphoteric Oxide Hydrates, Their Aqueous Solutions and Their Crystallizing Compounds. Part XIII. Silicates and Dissolved Silicon Dioxide Hydrate in Basic and Acidic Solutions

机译：两性氧化物水合物，它们的水溶液及其结晶化合物。第十三部分。硅酸盐和溶解二氧化硅水合物在碱性和酸性溶液中

获取原文
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Only anions of a mono- or a disilicic acid can be stable in aqueous solutions of alkali-metal silicates. The type which is present depends on the (H exp + ) of the solution. The two types are in equilibrium with each other, as in the cases of chromate ion with dichromate ion and stannate ion with distannate ion: 2 SiO sub 3 -- + H sub 2 O in equilibrium Si sub 2 O sub 5 -- + 2 OH-. Monosilicate exists at an (H exp + ) below that of 1 N sodium--hydroxide solution, and disilicate exists from 10 exp -13 exp 5 to 10 exp -10 exp 9 . This is proven by diffusion experiments and by measurements of absorptivity. The silicates are even more aggregated above (H exp + ) = 10 exp -10 exp 9 , but are unstable in solution. They usually precipitate after a longer or shorter time as a voluminous flocculate of silicon dioxide hydrate. The two hydrogen atoms of disilicic acid have quite different dissociation constants; the acidic properties of the first hydrogen atom are not inconsiderable. The ''silicate'' dissolved in acidic solutions which was recognized as being monomolecular (and which - independently of the experimental conditions - remains for a certain time) is of a different nature from the ''mono-'' and ''disilicates'' present in the alkaline region. It represents a more basic form of silicon dioxide hydrate in comparison to ''mono-'' or ''disilicate.'' This is shown by the solubility experiments and the optical absorption measurements. Its conversion into the silicate form is recognizable during thermometric and conductometric titration of acidic solutions of silicon dioxide hydrate with sodium hydroxide solution. (ERA citation 04:019908)

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号