Unformatted text preview: and Cl- is in a 1 state Cl2 ,the two Cl atoms are identical and should have the same oxidation state.But if their total is to be zero, each oxidation state state must itself be 0 rules
1.The O.S.of an individual atom in a free element(uncombined with other element) is 0. 2.The total of the O.S.of all the atoms in (a) Neutral species, such as isolated atoms,molecules,and formula units,is 0. (b)an ion is equal to the charge on the ion. 3.In their compounds,the group 1 metals have an O.S. of +1 and the group 2 metals have an O.S. of +2. 4.In its compounds, the O.S. of fluorine 1. 5.In its compounds, hydrogen has an O.S. of 1. 6.In its compounds,oxygen has an O.S. of 2. 7.In binary(two-element) compounds with metals, group 17 elements have an O.S. of 1; group 16 elements ,2; group 15 elements,-3. Oxidation state =O.S. ? As signing Oxidation States.What is the oxidation state of the underlined element in each of the following? (a)P4; (b)NaH; (c)Fe3O4. solution (a) P4:This formula represents a molecule of elemental phosphorus.for an atom of a free element ,the O.S. = 0(rule 1).The O.S. of P in P4 is 0. (b) NaH:This is the formula unit of the ionic compound sodium hydride.Rule3 states that the O.S. of Na is +1.Rule 5 indicates that H should also have O.S. +1;If both atoms had O.S. +1,the total for the formula unit would be +2.This violates rule 2.Rule 2 and rule 3take precedence over rule 5.Na has O.S. +1;the total for the formula unit is 0;and the O.S. of H is 1. (c) Fe3O4;The total of the oxidation states of four O atoms is 8.For three Fe atoms,the total must be +8.The O.S. per Fe atom is 8/3 or + 22/3 . 3-5 Naming Compounds : Organic and Inorganic Compounds Throughout this chapter, we have referred to compounds mostly by their formulas,but we do need to give them names. When we know the name of a compound, we can Look up properties in a handbook Locate a chemical on a storeroom shelf Discuss an experiment with a colleague What we need is a systematic method of assigning names-a system of nomenclature.Several systems are used ,and we will introduce each at an appropriate point in the text. Compounds formed by carbon and hydrogen or carbon and hydrogen together with oxygen,nitrogen and a few other elements are organic compounds.They are generally considered in a special branch of chemistry with its own set of nomenclature rules-organic chemistry. Compounds that do not fit this description are inorganic compounds.The branch of chemistry that concerns itself with the study of these compounds is called inorganic chemistry 3-6 Names and Formulas of Inorganic Compounds
Binary Compounds of Metals and Nonmetals Binary Compounds are those formed between two element.If one of the elements is a metal and the other a nonmetal,the binary compounds is usually made up of ions;that is ,it is a binary ionic compound.To name a binary compound of a metal and a nonmetal Write the unmodified name of the metal 4 Then write the name of the nonmetal,modified to end in ide Name unchanged NaCl = &qu...
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- Spring '10
- Molecule, Ion