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  2. Phosphorus pentasulfide - Wikipedia

    en.wikipedia.org/wiki/Phosphorus_pentasulfide

    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 ...

  3. Marine biogeochemical cycles - Wikipedia

    en.wikipedia.org/wiki/Marine_biogeochemical_cycles

    Since liquid water flows, ocean waters cycle and flow in currents around the world. Since water easily changes phase, it can be carried into the atmosphere as water vapour or frozen as an iceberg. It can then precipitate or melt to become liquid water again. All marine life is immersed in water, the matrix and womb of life itself. [7]

  4. Chemical cycling - Wikipedia

    en.wikipedia.org/wiki/Chemical_cycling

    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 ...

  5. Water-reactive substances - Wikipedia

    en.wikipedia.org/wiki/Water-reactive_substances

    Water-reactive substances [1] are those that spontaneously undergo a chemical reaction with water, often noted as generating flammable gas. [2] Some are highly reducing in nature. [ 3 ] Notable examples include alkali metals , lithium through caesium , and alkaline earth metals , magnesium through barium .

  6. Water cycle - Wikipedia

    en.wikipedia.org/wiki/Water_cycle

    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.

  7. Antimony pentasulfide - Wikipedia

    en.wikipedia.org/wiki/Antimony_pentasulfide

    Like many sulfides, this compound liberates hydrogen sulfide upon treatment with strong acids such as hydrochloric acid. [3]6 HCl + Sb 2 S 5 → 2 SbCl 3 + 3 H 2 S + 2 S. Analysis by Mössbauer spectroscopy indicates that this compound is a derivative antimony(III), [4] explaining the production of antimony(III) chloride, rather than antimony(V) chloride, upon acidification.

  8. Thermochemical cycle - Wikipedia

    en.wikipedia.org/wiki/Thermochemical_cycle

    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.

  9. Water splitting - Wikipedia

    en.wikipedia.org/wiki/Water_splitting

    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.