Search results
Results from the WOW.Com Content Network
Water is the medium of the oceans, the medium which carries all the substances and elements involved in the marine biogeochemical cycles. Water as found in nature almost always includes dissolved substances, so water has been described as the "universal solvent" for its ability to dissolve so many substances.
The ocean plays a key role in the water cycle as it is the source of 86% of global evaporation. [2] The water cycle involves the exchange of energy, which leads to temperature changes. When water evaporates, it takes up energy from its surroundings and cools the environment. When it condenses, it releases energy and warms the environment.
A biogeochemical cycle, or more generally a cycle of matter, [1] is the movement and transformation of chemical elements and compounds between living organisms, the atmosphere, and the Earth's crust. Major biogeochemical cycles include the carbon cycle, the nitrogen cycle and the water cycle. In each cycle, the chemical element or molecule is ...
In organic synthesis, the complex diethylaniline·borane (DEANB) is used as a reducing agent. [4] Diethylaniline and dimethylaniline are both used as acid-absorbing bases. The advantage to the diethyl derivative is that [C 6 H 5 NEt 2 H]Cl is non-hygroscopic, in contrast to [C 6 H 5 NMe 2 H]Cl. [5]
An example chemical cycle, a schematic representation of a Nitrogen cycle on Earth. This process results in the continual recycling of nitrogen gas involving the ocean. Chemical cycling describes systems of repeated circulation of chemicals between other compounds, states and materials, and back to their original state, that occurs in space ...
Catalytic cycle for the Wacker process. [8] The initial stoichiometric reaction was first reported by Francis Clifford Phillips in his doctoral dissertation on the composition of Pennsylvanian natural gas defended in 1893. [9] This net reaction can also be described as follows: [PdCl 4] 2 − + C 2 H 4 + H 2 O → CH 3 CHO + Pd + 2 HCl + 2 Cl −
Consisting of a phenyl group (−C 6 H 5) attached to an amino group (−NH 2), aniline is the simplest aromatic amine. It is an industrially significant commodity chemical, as well as a versatile starting material for fine chemical synthesis. Its main use is in the manufacture of precursors to polyurethane, dyes, and other industrial chemicals.
Consequently, a thermochemical cycle with i steps can be defined as sequence of i reactions equivalent to water-splitting and satisfying equations (4), (5) and (10). The key point to remember in that case is that the process temperature T H can theoretically be arbitrary chosen (1000K as a reference in most of the past studies, for high ...