LAB – NOMENCLATURE
Based on Roger Williams University Nomenclature Lab (Chem 191)
Nomenclature is a set or system of names. The nomenclature that is used in chemistry is based on the IUPAC (International Union of Pure and Applied Chemists) convention. The basic rule is that the name of a particular compound must be completely unambiguous – that is, one name means one particular compound and no other. The simplified rules that follow can be used to name the majority of inorganic compounds.
RULES FOR NOMENCLATURE OF SIMPLE COMPOUNDS
RULE 1
The names of ionic compounds are derived from the positive ions and the negative ions in the compound. For nonionic binary compounds, consider the compound to be composed of 2 parts, one positive and one negative.
RULE 2
The positive ion or part is always named first and written first in formulas. The basic rule: if an element is to the left of another element in the periodic table or below it, it is always less electronegative and named or written first.
RULE 3
BINARY COMPOUNDS (2 ELEMENTS ONLY)
(a) Positive element with a fixed oxidation state (metal or hydrogen):
Name of positive element + “negative stem” with –ide suffix.
e.g. CaCl2 calcium chloride
(b) Positive element with a variable oxidation state (metal): STOCK SYSTEM where the oxidation number of a metal is specified with a Roman numeral in parenthesis and the negative ion is named as in (a) above.
OLD METHOD stem name of metal (usually Latin) with the –ic indicating higher oxidation number and –ous the lower.
e.g. CuCl copper (I) chloride or cuprous chloride
CuCl2 copper (II) chloride or cupric chloride
(c) TWO NONMETALS: named as illustrated in (a) with prefixes to indicate how many of each element is present. EXCEPTION: if the first element consists of only one atom, the prefix for it is understood.
e.g. CO carbon monoxide
N2O3 dinitrogen trioxide
Prefixes
1-mono 6-hexa
2-di 7-hepta
3-tri 8-octa
4-tetra 9-nona
5-penta 10-deca
(d) In general, the –ide ending means binary compounds.
EXCEPTIONS:
NH4Cl ammonium chloride (ammonium salts)
Mg(OH)2 magnesium hydroxide (metal hydroxides)
CuCN copper (I) cyanide (metal cyanides)
(e) Binary Acids: i.e. hydrogen plus a nonmetal
In gas phase, named as in (a):
HCl (g) hydrogen chloride
In water solution: hydro (prefix) + negative stem + -ic acid
HCl (aq) hydrochloric acid
RULE 4
OTHER COMPOUNDS: compounds composed of three (or more) elements, most commonly a metal ion or hydrogen combined with a polyatomic ion ( a non-metal, or occasionally a transition metal, combined with oxygen, as a general rule). Generally, it is best to memorize the polyatomic ions, along with their charges. With a few exceptions, all end in –ate or –ite. Compounds composed of metals plus these polyatomic ions are named as in (a) or (b) above, except that the name of the polyatomic ion is used in place of the nonmetallic ion. (The names and formulas of various polyatomic ions are given on a sheet, just before the worksheet.
e.g. NaC2H3O2 sodium acetate
Cu(BrO3)2 copper (II) bromate or cupric bromate
Ni(NO3)3 nickel (III) nitrate
(NH4)2SO4 ammonium sulfate
When the polyatomic ion is combined with hydrogen, the compound is named as an acid by changing the –ate suffix to –ic or an –ite ending to –ous and adding the word acid to the name.
e.g. HC2H3O2 acetic acid
HBrO3 bromic acid
HNO2 nitrous acid
This is a partial list of inorganic ions. Many other ions can be named by recognizing that if an element is in the same periodic family, it should form similar ions with similar names.
BrO- hypobromite MnO4- permanganate
BrO2- bromite NH4+ ammonium
BrO3- bromate NO3- nitrate
BrO4- perbromate NO2- nitrite
C2O42- oxalate O22- peroxide
C2H3O2- acetate OH- hydroxide
CN- cyanide PO43- phosphate
CO32- carbonate SO42- sulfate
ClO- hypochlorite SO32- sulfite
ClO2- chlorite AsO43- arsenate
ClO3- chlorate AsO33- arsenite
ClO4- perchlorate
Cr2O72- dichromate
CrO42- chromate
H2PO4- dihydrogen phosphate
HCO3- hydrogen carbonate (bicarbonate)
HCOO- formate
HPO42- hydrogen phosphate
HS- hydrogen sulfide
HSO3- hydrogen sulfite
HSO4- hydrogen sulfate
Hg22+ mercury (I)
IO- hypoiodite
IO2- iodite
IO3- iodate
IO4- periodate
REPORT SHEET
NOMENCLATURE WORKSHEET
METALLIC COMPOUNDS
1.______chromium (III) chloride 2. ______gallium phosphate
3.______copper (I) sulfate 4. ______barium acetate
5.______strontium hydrogen carbonate 6. ______calcium nitride
7.______potassium chromate 8. ______magnesium carbonate
9.______strontium dichromate 10.______ammonium phosphate
11. ______Al2(SO4)3
12. ______AuCl3
13. ______Ca(C2H3O2)2
14. ______K3AsO4
15. ______CuSO3
16. ______Cs2HPO4
17. ______Zn(BrO3)2
18. ______(NH4)2CO3
19. ______BeSO4
20. ______FeO
NONMETALLIC COMPOUNDS
21. ______PBr3 22. ______CF4
23. ______SO3 24. ______CO2
NONMETALLIC COMPOUNDS….continued
25. ______N2O 26. ______IF5
27. ______SbCl3 28. ______SiO2
29. ______BrF5 30. ______SiC
31.______tetraphosphorus decoxide
32.______diarsenic trioxide
33.______carbon tetrachloride
34.______carbon monoxide
35. ______phosphorus pentabromide
36. ______bromine dioxide
37. ______carbon monosulfide
38. ______phosphorus pentachloride
39. ______dintrogen tetroxide
40. ______tellurium dioxide
ACIDS
41.______hydrochloric acid 42. ______sulfuric acid
43. ______chromic acid 44. ______bromous acid
45. ______nitric acid 46.______acetic acid
47.______perchloric acid 48.______phosphorus acid
49. ______hypobromous acid 50.______hydroiodic acid
ACIDS…continued….
51.______HBr
52.______HNO2
53.______HClO
54.______H2SO3
55.______H3PO4
56. ______HClO3
57. ______HNO2
58.______H2CO3
59.______HF
60. ______HIO4
MIXED REVIEW
61. ______tin (IV) oxide 62.______zinc permanganate
63. ______ammonium hydroxide 64. ______silver nitrate
65. ______iron (II) dichromate 66.______silver bicarbonate
67. ______formic acid 68.______nitrogen triiodide
69. ______boron trifluoride 70. ______hydrocyanic acid
71.______hydrosulfuric acid 72.______Au3(PO4)2
73.______CuHSO4 74.______BI3
75.______FeCl3
MORE MIXED REVIEW
76.______FeAsO4
77.______Arsenous acid
78.______copper (II) oxalate
79.______potassium iodate
80.______ammonium dichromate
81. ______magnesium peroxide
82.______gold (II) cyanide
83.______potassium hydroxide
84.______lead (IV) oxide
85.______tungsten (IV) oxide
86. ______palladium (II) cyanide
87.______BF3
88.______NH4I
89.______CoCl3
90. ______NO3
91.______FeAsO3
92.______mercury (II) cyanide
93.______HBrO2
94.______HClO3
95.______lead (II) acetate
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