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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).
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 ...
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 ...
The structure of this salt was verified by X-ray crystallography. The respective C–O and C–N distances are 1.174(8) and 1.192(7) Å , consistent with the O=C=N − description. Ammonium cation [NH 4 ] + forms hydrogen bonds with cyanate anion O=C=N − , but to N, not to O. [ 1 ]
This would result in the geometry of a regular tetrahedron with each bond angle equal to arccos(− 1 / 3 ) ≈ 109.5°. However, the three hydrogen atoms are repelled by the electron lone pair in a way that the geometry is distorted to a trigonal pyramid (regular 3-sided pyramid) with bond angles of 107°.
Ammonium heptamolybdate is the inorganic compound whose chemical formula is (NH 4) 6 Mo 7 O 24, normally encountered as the tetrahydrate.A dihydrate is also known. It is a colorless solid, often referred to as ammonium paramolybdate or simply as ammonium molybdate, although "ammonium molybdate" can also refer to ammonium orthomolybdate, (NH 4) 2 MoO 4, and several other compounds.
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]
Ammonium formate can be used for reductive amination of aldehydes and ketones (Leuckart reaction), by the following reaction: [5] Ammonium formate can be used as a mobile phase additive in high performance liquid chromatography (HPLC), and is suitable for use with liquid chromatography-mass spectrometry (LC/MS).