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[1] [2] [3] Introduced by Gilbert N. Lewis in his 1916 article The Atom and the Molecule, a Lewis structure can be drawn for any covalently bonded molecule, as well as coordination compounds. [4] Lewis structures extend the concept of the electron dot diagram by adding lines between atoms to represent shared pairs in a chemical bond.
α-Calcium nitride adopts an anti-bixbyite structure, similar to Mn 2 O 3, except that the positions of the ions are reversed: calcium (Ca 2+) take the oxide (O 2−) positions and nitride ions (N 3−) the manganese (Mn 3+). In this structure, Ca 2+ occupies tetrahedral sites, and the nitride centres occupy two different types of octahedral ...
The most common Lewis bases are anions. The strength of Lewis basicity correlates with the pK a of the parent acid: acids with high pK a 's give good Lewis bases. As usual, a weaker acid has a stronger conjugate base. Examples of Lewis bases based on the general definition of electron pair donor include: simple anions, such as H − and F −
Calcium oxide is usually made by the thermal decomposition of materials, such as limestone or seashells, that contain calcium carbonate (CaCO 3; mineral calcite) in a lime kiln. This is accomplished by heating the material to above 825 °C (1,517 °F), [ 6 ] [ 7 ] a process called calcination or lime-burning , to liberate a molecule of carbon ...
The hyponitrite ions can act as a bidentate ligand in either bridging or chelating mode. There is a bridging cis-hyponitrite group in the red dinuclear form of nitrosyl pentammine cobalt(III) chloride, [Co(NH 3) 5 NO]Cl 2. [4] Hyponitrite can reduce elemental iodine to hydroiodic acid: [4] N 2 O 2− 2 + 3 I 2 + 3 H 2 O → NO −
Lewis’ early papers also reveal an unusually advanced awareness of J. W. Gibbs's and P. Duhem's ideas of free energy and thermodynamic potential. These ideas were well known to physicists and mathematicians, but not to most practical chemists, who regarded them as abstruse and inapplicable to chemical systems.
BAPTA (1,2-bis(o-amino phenoxy)ethane-N,N,N′,N′-tetraacetic acid) is a calcium-specific aminopolycarboxylic acid. The presence of four carboxylic acid functional groups makes possible the binding of two calcium ions. The extensive flexibility of the carboxylate ligands is critical to the coordination of calcium and other metal ions.
The first term on the right-hand side is for an ideal gas. The remaining terms quantify the departure from the ideal gas law with changing pressure, P {\displaystyle P} . It can be shown by statistical mechanics that the second virial coefficient arises from the intermolecular forces between pairs of molecules, the third virial coefficient ...