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Aluminium nitrate cannot be synthesized by the reaction of aluminium with concentrated nitric acid, as the aluminium forms a passivation layer. Aluminium nitrate may instead be prepared by the reaction of nitric acid with aluminium(III) chloride. Nitrosyl chloride is produced as a by-product; it bubbles out of the solution as a gas.
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 ...
The Haber process, [1] also called the Haber–Bosch process, is the main industrial procedure for the production of ammonia. [2][3] It converts atmospheric nitrogen (N 2) to ammonia (NH 3) by a reaction with hydrogen (H 2) using a finely divided iron metal catalyst: This reaction is slightly favorable in terms of enthalpy, but is disfavored in ...
Nitrification is the biological oxidation of ammonia to nitrate via the intermediary nitrite. Nitrification is an important step in the nitrogen cycle in soil. The process of complete nitrification may occur through separate organisms [ 1 ] or entirely within one organism, as in comammox bacteria.
Atomic layer deposition. Schematic illustration of one reaction cycle of the ALD process, using the trimethylaluminium (TMA) -water process to make thin aluminium oxide films as (simplified) example. There, the starting surface contains hydroxyls (OH groups) as reactive sites; Step 1 is the reaction of TMA; Step 2 is a purge or evacuation step ...
Without supplies of fixed nitrogen entering the marine cycle, the fixed nitrogen would be used up in about 2000 years. [83] Phytoplankton need nitrogen in biologically available forms for the initial synthesis of organic matter. Ammonia and urea are released into the water by excretion from plankton.
Anammox, an abbreviation for "anaerobic ammonium oxidation", is a globally important microbial process of the nitrogen cycle [ 1 ] that takes place in many natural environments. The bacteria mediating this process were identified in 1999, and were a great surprise for the scientific community. [ 2 ] In the anammox reaction, nitrite and ammonium ...
As dissimilatory nitrate reduction to ammonium is an anaerobic respiration process, marine microorganisms capable of performing DNRA are most commonly found in environments low in O 2, such as oxygen minimum zones (OMZs) in the water column, or sediments with steep O 2 gradients. [11] [12] The oceanic nitrogen cycle with the role of DNRA.