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Titanium tetrachloride is also used to make titanium dioxide, e.g., for use in white paint. [52] It is widely used in organic chemistry as a Lewis acid, for example in the Mukaiyama aldol condensation. [53] In the van Arkel–de Boer process, titanium tetraiodide (TiI 4) is generated in the production of high purity titanium metal. [54]
The surface of titanium and of titanium-rich alloys oxidizes immediately upon exposure to air to form a thin passivation layer of titanium oxide, mostly titanium dioxide. [27] This layer makes it resistant to further corrosion, aside from gradual growth of the oxide layer, thickening to ~25 nm after several years in air.
For example, phosphoric acid in the form of naval jelly is often applied to ferrous tools or surfaces to remove rust. Corrosion removal should not be confused with electropolishing, which removes some layers of the underlying metal to make a smooth surface. For example, phosphoric acid may also be used to electropolish copper but it does this ...
This form of corrosion is usually caused by a combination of corrosion and cyclic stress. [58] Measuring and controlling this is difficult because of the many factors at play including the nature or form of the stress cycle. The stress cycles cause localized work hardening. So avoiding stress concentrators such as holes etc would be good ...
Soil erosion is the denudation or wearing away of the upper layer of soil. It is a form of soil degradation. This natural process is caused by the dynamic activity of erosive agents, that is, water, ice (glaciers), snow, air (wind), plants, and animals (including humans).
Soil chemistry is the study of the chemical characteristics of soil.Soil chemistry is affected by mineral composition, organic matter and environmental factors. In the early 1870s a consulting chemist to the Royal Agricultural Society in England, named J. Thomas Way, performed many experiments on how soils exchange ions, and is considered the father of soil chemistry. [1]
Smooth biological soil crusts occur in hot deserts where the soil does not freeze, and consist mostly of cyanobacteria, algae, and fungi. Thicker and rougher crusts occur in areas where higher precipitation results in increased cover of lichen and mosses, and frost heaving of these surfaces cause microtopography such as rolling hills and steep ...
The Goldschmidt classification, [1] [2] developed by Victor Goldschmidt (1888–1947), is a geochemical classification which groups the chemical elements within the Earth according to their preferred host phases into lithophile (rock-loving), siderophile (iron-loving), chalcophile (sulfide ore-loving or chalcogen-loving), and atmophile (gas-loving) or volatile (the element, or a compound in ...