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  2. Ammonium - Wikipedia

    en.wikipedia.org/wiki/Ammonium

    Ammonium is a modified form of ammonia that has an extra hydrogen atom. It is a positively charged molecular ion with the chemical formula NH + 4 or [NH 4] +.It is formed by the addition of a proton (a hydrogen nucleus) to ammonia (NH 3).

  3. Ammonia (data page) - Wikipedia

    en.wikipedia.org/wiki/Ammonia_(data_page)

    195.4 K (−77.75 °C), 6.060 kPa: Critical point: 405.5 K (132.3 °C), 11.300 MPa: Std enthalpy change of fusion, Δ fus H o +5.653 kJ/mol Std entropy change of fusion, Δ fus S o +28.93 J/(mol·K) Std enthalpy change of vaporization, Δ vap H o +23.35 kJ/mol at BP of −33.4 °C Std entropy change of vaporization, Δ vap S o +97.41 J/(mol·K ...

  4. Coordination geometry - Wikipedia

    en.wikipedia.org/wiki/Coordination_geometry

    In a crystal structure the coordination geometry of an atom is the geometrical pattern of coordinating atoms where the definition of coordinating atoms depends on the bonding model used. [1] For example, in the rock salt ionic structure each sodium atom has six near neighbour chloride ions in an octahedral geometry and each chloride has ...

  5. Nitrogen pentahydride - Wikipedia

    en.wikipedia.org/wiki/Nitrogen_pentahydride

    One structure is trigonal bipyramidal molecular geometry type NH 5 molecule. Its nitrogen atom and hydrogen atoms are covalently bounded, and its symmetry group is D 3h. [1] Another predicted structure of nitrogen pentahydride is an ionic compound, composed of an ammonium ion and a hydride ion (NH 4 + H −). Until now, no one has synthesized ...

  6. Chemical structure - Wikipedia

    en.wikipedia.org/wiki/Chemical_structure

    A chemical structure of a molecule is a spatial arrangement of its atoms and their chemical bonds. Its determination includes a chemist 's specifying the molecular geometry and, when feasible and necessary, the electronic structure of the target molecule or other solid.

  7. Reinecke's salt - Wikipedia

    en.wikipedia.org/wiki/Reinecke's_salt

    The chromium atom is surrounded by six nitrogen atoms in an octahedral geometry. The NH 3 ligands are mutually trans and the Cr–NCS groups are linear. The salt crystallizes with one molecule of water. [1] It was first reported in 1863. [3]

  8. Ammonia - Wikipedia

    en.wikipedia.org/wiki/Ammonia

    The hazards of ammonia solutions depend on the concentration: 'dilute' ammonia solutions are usually 5–10% by weight (< 5.62 mol/L); 'concentrated' solutions are usually prepared at >25% by weight. A 25% (by weight) solution has a density of 0.907 g/cm 3 , and a solution that has a lower density will be more concentrated.

  9. Ammonium perrhenate - Wikipedia

    en.wikipedia.org/wiki/Ammonium_perrhenate

    The crystal structure of APR resembles that of scheelite, with atomic cation is replaced by ammonium. The pertechnetate (NH 4 TcO 4 ), periodate (NH 4 IO 4 ), tetrachlorothallate (NH 4 TlCl 4 ), and tetrachloroindate (NH 4 InCl 4 ) follow this motif. [ 4 ]