Chemical names {chemical naming} have formats.
name from formula
Chemical name comes from chemical formula. In general, write name for each symbol in formula in same sequence as in formula, in order of increasing electronegativity.
To write correct symbol names, first check formula for complex ions.
Then check for atom or ion valences or charges.
Write first atom or ion name.
If molecule is ionic, and metal ion can have more than one valence number, write metal-ion valence in roman numerals in parentheses.
For covalent molecules, if number of attached oxygens or other atoms is one, write "mono-". If two, write "di-". If three, write "tri-". If four, write "tetra-". If five, write "penta-". If six, write "hexa-".
If molecule is ionic, write second-ion root. If molecule is covalent, write root of atom with attached oxygens or other atoms.
Always add "-ide" to root.
For example, the ionic compound FeCl2 [2 is subscript] is iron (II) chloride. The covalent compound SO2 [2 is subscript] is sulfur dioxide.
Acid names {acid naming} have the following rules. If anion name ends in "-ide", start with "hydro-", add anion root, and then add "-ic acid", as in hydrochloric acid. If anion name ends in "-ate", start with anion root and then add "-ic acid", as in sulfuric acid. If anion name ends in "-ite", start with anion root and then add "-ous acid", as in sulfurous acid.
Polyatomic ion names {complex ion naming} can have five parts.
hydrogen
If ion has one hydrogen, begin name with "hydrogen". For two hydrogens, begin with "dihydrogen". For three hydrogens, begin with "trihydrogen".
oxygen
If ion central atom can attach oxygen in more than two ways, use prefix "per-" for ion with the most oxygen atoms or prefix "hypo-" for ion with the least oxygen atoms.
root
Then use central atom root. Root for C is carbon-. Root for N is nitr-. Root for O is ox-. Root for P is phosph-. Root for S is sulf-. Root for Cl is chlor-. Root for Mn is mangan-.
oxygen suffix
If ion central atom can attach oxygen in at least two ways, add "-ite" to root for ion with fewer oxygens or add "-ate" to root for ion with more oxygens.
ion
Then add the word "ion".
example
ClO4- [4 is subscript and - is superscript] is perchlorate ion, ClO3- [3 is subscript and - is superscript] is chlorate ion, ClO2- [2 is subscript and - is superscript] is chlorite ion, and ClO- [- is superscript] is hypochlorite ion.
CO3-- [3 is subscript and -- is superscript] is carbonate ion.
NO3- [3 is subscript and - is superscript] is nitrate ion and NO2- [2 is subscript and - is superscript] is nitrite ion.
O2-- [2 is subscript and -- is superscript] is peroxide ion.
PO4--- [4 is subscript and --- is superscript] is phosphate ion.
SO3-- [3 is subscript and -- is superscript] is sulfite ion. SO4-- [4 is subscript and -- is superscript] is sulfate ion.
MnO4- [4 is subscript and - is superscript] is permanganate ion.
special
Polyatomic ions can have special names. NH4+ [4 is subscript and + is superscript] is ammonium ion. OH- [- is superscript] is hydroxide ion. CN- [- is superscript] is cyanide ion. C2H3O2- [2 and 3 are subscripts and - is superscript] is acetate ion. HCO3- [3 is subscript and - is superscript] is bicarbonate ion.
Find chemical formulas {chemical formula} {formula, chemistry} using percent composition. For each element, divide percent composition by atomic mass units, to find number of elements per molecular weight. Then divide smallest number into others. If all answers are close to whole numbers, use whole numbers as subscripts in chemical formula. If answers are not all whole numbers, multiply answers by two, then three, then four, and so on, until answers are whole numbers. Then use whole numbers as subscripts in chemical formula.
Chemical formula comes from chemical name {formula from name}. Because molecule has zero total charge, sum of ion charges and atom valences must equal zero. First, write atom or complex-ion symbols in same sequence as in name. Remember or look up ion or atom charges or valence. For atoms or complex ions, assign number subscripts so sum, of charge or valence times subscript, adds to zero.
Ion names follow rules {simple ion naming}. If cation has one atom, use atom name followed by the word ion. For example, Na+ [+ is superscript] is sodium ion. If anion has one atom, use atom root followed by "-ide". For example, O2- [2 is subscript and - is superscript] is oxide ion.
5-Chemistry-Inorganic-Chemical
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Date Modified: 2022.0225