Formula oxidation number

Compound Structural formula Molecular formula Oxidation number... 

Species Molecular Formula Oxidation Number of Nitrogen... 

Chemical Formula Oxidation Number of 1st Element Name of Compound ... 

The oxidation-number system is easily extended to include other coordination compounds. Even the interesting substances represented by the formulas Na4Ni(CN)4 and K4Pd(CN)4 create no nomenclature problem they become sodium tetracyanonickelate(0) and potassium tetracyanopaHadate(0), respectively. 

Parent amine Amine Registry Number PK amine Oxide molecular formula Oxide Registry Number TpK N-oxide... 

In most of its compounds nickel has a +2 oxidation number, but it is possible to get a higher state by heating Ni(OH)2 with hypochlorite ion in basic solution. Hypochlorite ion, CIO-, is one of the stronger oxidizing agents at our disposal in basic solution. There is considerable argument about the formula of the black solid that is formed, but we shall label it as Ni208 and write the equation... 

The other procedure which is of value in the calculation of the equivalents of substances is the oxidation number method. This is a development of the view that oxidation and reduction are attended by changes in electronic charge and was originally developed from an examination of the formulae of the initial and final compounds in a reaction. The oxidation number (this will be abbreviated to O.N.) of an element is a number which, applied to that element in a particular compound, indicates the amount of oxidation or reduction which is required to convert one atom of the element from the free state to that in the compound. If oxidation is necessary to effect the change, the oxidation number is positive, and if reduction is necessary, the oxidation number is negative. 

Ionic compounds are named by starting with the name of the cation (with its oxidation number if more than one charge is possible), followed by the name of the anion hydrates are named by adding the word hydrate, preceded by a Greek prefix indicating the number of water molecules in the formula unit. 

Charge number Chemical formula Name Oxidation number of central element Charge number Chemical formula Name Oxidation number of central clement... 

The formula above represents phosphoric acid. Which of these is the proper oxidation number for... 

We learned to write formulas of ionic compounds in Chaps. 5 and 6. We balanced the charges to determine the number of each ion to use in the formula. We could not do the same thing for atoms of elements in covalent compounds, because in these compounds the atoms do not have charges. In order to overcome this difficulty, we define oxidation numbers, also called oxidation states. 

In Sec. 13.2 we will learn to determine oxidation numbers from the formulas of compounds and ions. We will learn how to assign oxidation numbers from electron dot diagrams and more quickly from a short set of rules. We use these oxidation numbers for naming the compounds or ions (Chap. 6 and Sec. 13.4) and to balance equations for oxidation-reduction reactions (Sec. 13.5). In Sec. 13.3 we will learn to predict oxidation numbers for the elements from their positions in the periodic table in order to be able to predict formulas for their compounds and ions. 

With these rules, we can quickly and easily calculate the oxidation numbers of an element most of the time from the formulas of its compounds. 

The more electronegative element will take the negative oxidation state, (a) The maximum oxidation state of sulfur is +6 the most common negative oxidation number of oxygen is -2. Therefore, it takes three oxygen atoms to balance one sulfur atom, and the formula is SO v (b) The maximum oxidation state of carbon is +4 the only oxidation number of fluorine in its compounds is - 1. Therefore, it takes four fluorine atoms to balance one carbon atom, and the formula is CF4,... 

If phosphorus pentoxide were POs, phosphorus would have an oxidation number of + 10, which exceeds its group number. The maximum oxidation number that phosphorus can have is + 5 (from group VA), and so the formula is P205. (The compound cannot be a peroxide it was named oxide. )... 

Hydrogen is capable of forming compounds with all elements except the noble gases. In compounds with nonmetals, hydrogen usually behaves like a metal instead of a nonmetal. Therefore, when hydrogen combines with a nonmetal, it usually has a +1 oxidation number. When hydrogen combines with a metal, it usually has a —1 oxidation number. Hydrogen compounds with the transition metals are usually nonstoichiometric. Nonstoichiometric compounds have no definite formula. 

Next, rule 10 is used for determining all oxidation numbers of all elements that rules 1 through 8 do not cover (this must be all but one element in a formula), and then assigning the remaining elements oxidation numbers, knowing that the total must add up to either zero or the ionic charge. 

Notice that the oxidation number per atom is multiplied by the number of atoms in the formula unit. 

The names of cations can be designated quite simply, although it is absolutely necessary to specify charge, either directly using charge number or indirectly using oxidation number. The parentheses in these examples of formulae are optional. 

An interesting series of vanadium complexes whose formal oxidation number is 4+ has been reported by Davison et al. (75). They have investigated the solution spectra of the ions of general formula V(S2C2R2)3, where R = —C6H5, —CF3, —CN. They find g 1.98 and /f 60xl0-4 cm-1. They do not, however, consider these complexes to have one unpaired spin on the vanadium but rather consider the complex to be V(III) plus a radical anion with the two electrons in vanadium orbitals being paired up. 

Ionic charges and oxidation numbers. If the formula of a charged coordination entity is to be written without lhat of the counterion, the churge is indicated outside the square bracket as a right superscript, wiih the number before the sign. The oxidation number of a central atom may be represented by a roman numeral used as a right superscript on the element symbol. 

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