Search results
Results from the WOW.Com Content Network
Ammonia is used in numerous different industrial applications requiring carbon or stainless steel storage vessels. Ammonia with at least 0.2% by weight water content is not corrosive to carbon steel. NH 3 carbon steel construction storage tanks with 0.2% by weight or more of water could last more than 50 years in service. [141]
Typical Lewis bases are conventional amines such as ammonia and alkyl amines. Other common Lewis bases include pyridine and its derivatives. Some of the main classes of Lewis bases are amines of the formula NH 3−x R x where R = alkyl or aryl. Related to these are pyridine and its derivatives. phosphines of the formula PR 3−x Ar x.
[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.
For example, R-22 has one carbon atom, one hydrogen atom (2−1 = 1), two fluorine atoms, and one chlorine atom (4−2−1 = 1), so it is chlorodifluoromethane, while R-134 has two carbon atoms (2−1 = 1), two hydrogen atoms (3−1 = 2), four fluorine atoms, and no chlorine atoms (6−2−4 = 0), so it is one of the tetrafluoroethanes. This ...
Compounds of group 16 with a formula DX 2 may also act as Lewis bases; in this way, a compound like an ether, R 2 O, or a thioether, R 2 S, can act as a Lewis base. The Lewis definition is not limited to these examples. For instance, carbon monoxide acts as a Lewis base when it forms an adduct with boron trifluoride, of formula F 3 B←CO.
[2] [3] [4] Various computational criteria for the presence of lone pairs have been proposed. While electron density ρ(r) itself generally does not provide useful guidance in this regard, the Laplacian of the electron density is revealing, and one criterion for the location of the lone pair is where L(r) = –∇ 2 ρ(r) is a local
Sample of chloropentamminecobalt chloride [CoCl(NH 3) 5]Cl 2, illustrating the vibrant colors typical of transition metal ammine complexes. Zinc(II) forms a colorless tetraammine with the formula [Zn(NH 3) 4] 2+. [13] Like most zinc complexes, it has a tetrahedral structure. Hexaamminenickel is violet, and the copper(II) complex is deep blue.
Table data (above) obtained from CRC Handbook of Chemistry and Physics 44th ed. The (s) notation indicates equilibrium temperature of vapor over solid. Otherwise temperature is equilibrium of vapor over liquid.