Search results
Results From The WOW.Com Content Network
Polyatomic ions often are useful in the context of acid–base chemistry and in the formation of salts. Often, a polyatomic ion can be considered as the conjugate acid or base of a neutral molecule. For example, the conjugate base of sulfuric acid (H 2 SO 4) is the polyatomic hydrogen sulfate anion (HSO − 4).
An ionic compound is named by its cation followed by its anion. See polyatomic ion for a list of possible ions. For cations that take on multiple charges, the charge is written using Roman numerals in parentheses immediately following the element name. For example, Cu(NO 3) 2 is copper(II) nitrate, because the charge of two nitrate ions (NO −
Polyatomic cations of the same element are named as the element name preceded by di-, tri-, etc., e.g.: Hg 2+ 2 dimercury(2+) Polyatomic cations made up of different elements are named either substitutively or additively, e.g.: PH + 4 phosphanium; SbF + 4 tetrafluorostibanium (substitutive) or tetrafluoridoantimony(1+)
This applies for both electrolytic and electrochemical cells, though the charge on them reverses. The red cat and an ox mnemonics are useful to remember the same. Red cat: Reduction at cathode; An ox: Anode for oxidation. [28] PANIC : Positive Anode, Negative Is Cathode; The words oxidation and anode, both begin with vowels.
Quaternary ammonium cation. The R groups may be the same or different alkyl or aryl groups. Also, the R groups may be connected. In organic chemistry, quaternary ammonium cations, also known as quats, are positively-charged polyatomic ions of the structure [NR 4] +, where R is an alkyl group, an aryl group [1] or organyl group.
In inorganic chemistry, Fajans' rules, formulated by Kazimierz Fajans in 1923, [1] [2] [3] are used to predict whether a chemical bond will be covalent or ionic, and depend on the charge on the cation and the relative sizes of the cation and anion. They can be summarized in the following table:
Polyhalogen ions are a group of polyatomic cations and anions containing halogens only. The ions can be classified into two classes, isopolyhalogen ions which contain one type of halogen only, and heteropolyhalogen ions with more than one type of halogen.
For simple polyatomic molecules with a "central atom" such as methane (CH 4) or carbon dioxide (CO 2), a MO diagram may show one of the identical bonds to the central atom. For other polyatomic molecules, an MO diagram may show one or more bonds of interest in the molecules, leaving others out for simplicity.