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Phosphorus pentasulfide is obtained by the reaction of liquid white phosphorus (P 4) with sulfur above 300 °C. The first synthesis of P 4 S 10 by Berzelius in 1843 [ 5 ] was by this method. Alternatively, P 4 S 10 can be formed by reacting elemental sulfur or pyrite , FeS 2 , with ferrophosphorus , a crude form of Fe 2 P (a byproduct of white ...
The sulfur–iodine cycle (S–I cycle) is a series of thermochemical processes used to produce hydrogen. The S–I cycle consists of three chemical reactions whose net reactant is water and whose net products are hydrogen and oxygen. All other chemicals are recycled. The S–I process requires an efficient source of heat.
In chemistry, thermochemical cycles combine solely heat sources (thermo) with chemical reactions to split water into its hydrogen and oxygen components. [1] The term cycle is used because aside of water, hydrogen and oxygen, the chemical compounds used in these processes are continuously recycled.
The cyclic light-dependent reactions occur only when the sole photosystem being used is photosystem I. Photosystem I excites electrons which then cycle from the transport protein, ferredoxin (Fd), to the cytochrome complex, b 6 f, to another transport protein, plastocyanin (Pc), and back to photosystem I. A proton gradient is created across the ...
Water cycle – moves water continuously on, above and below the surface shifting between states of liquid, solution, ice and vapour; Methane cycle – moves methane between geological and biogeochemical sources and reactions in the atmosphere; Hydrogen cycle – a biogeochemical cycle brought about by a combination of biological and ...
In the Calvin cycle, the energy from the electron carriers is used in carbon fixation, the conversion of carbon dioxide and water into carbohydrates. RPIA is essential in the cycle, as Ru5P generated from R5P is subsequently converted to ribulose-1,5-bisphosphate (RuBP), the acceptor of carbon dioxide in the first dark reaction of ...
Redox reactions are chemical reactions in which electrons are transferred from a donor molecule to an acceptor molecule. The underlying force driving these reactions is the Gibbs free energy of the reactants relative to the products. If donor and acceptor (the reactants) are of higher free energy than the reaction products, the electron ...
Phosphorus pentoxide crystallizes in at least four forms or polymorphs.The most familiar one, a metastable form [1] (shown in the figure), comprises molecules of P 4 O 10.Weak van der Waals forces hold these molecules together in a hexagonal lattice (However, in spite of the high symmetry of the molecules, the crystal packing is not a close packing [2]).