CHEMICAL NOMENCLATURE Nomenclature refers to the systematic naming of chemical substances. FORMULA
GIVEN NAME
Before systematic nomenclature, substances were given common names. These names usually had nothing to do with the elements that made up the compound: Examples: Archaic Name Formula Systematic Name Washing Soda Na2CO3 Lunar Caustic AgNO3
Oil of Vitriol H2SO4
Fortunately, we do not need to memorize thousands of seemingly random names. Ny knowing a few systems of nomenclature, we can name many substances. VALENCE refers to the actual (or assumed) charge on an atom of an element when it is in a compound. The valence of pure elements is zero. By convention, the element with positive valence is written first, followed by the one with a negative valence. Valence can be predicted through: 1. Position of the periodic table 2. By deduction from the formula. For IONIC compounds, VALENCE is equivalent to the ionic charge. e.g. Predict the valence of each element: CO UO2 SnS2 AuI3
SrF2 1) SIMPLE BINARY COMPOUNDS •
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contain 2 elements first element has a positive valence; second has a negative valence name of second ends in –ide first element has only 1 common valence e.g. MgBr2 _________________________________________________ Na2O ___________________________________________________ aluminum iodide _____________________ barium oxide ______________________ carbide
nitride
sulfide
fluoride
chloride
iodide
hydride
silicide
phosphide
arsenide
selenide
bromide
telluride
oxide
2)VARIABLE VALENCE BINARY COMPOUNDS These compounds have a first element with 2 (or more) possible positive valences (Refer to Table 1). Three systems have been developed to resolve this problem. I) IUPAC METHOD • a Roman numeral is used to indicate the positive valence tin (IV) chloride ____________________________ 1. I
lead (II) nitride ______________________________ 2. II
3. III
CoS ____________________________________________ 4. IV
5. V
PCl5 ____________________________________________ 6. VI
7. VII
8. VIII
9. IX
10. X
II) –ous / ­ic METHOD’ •
names are often based on the Latin names (cuprum, ferrus, stannum, plumbum, aurum, mercurum) the –ous suffix indicates the lower valence the –ic suffix indicates the higher valence •
•
ferric oxide ____________________ PbCl2 ________________________________________ ferrous oxide __________________ CuO _________________________________________ III) Greek Prefix Method • Greek prefixes can be used to indicate the number of atoms in a compound (unless there is only one of the first element) • do not need to consider valences of the elements ☺ •
can be used for any binary compound (usually nonmetals) P2O5 ____________________________________________________________________________ Mg3N2 _________________________________________________ nitrogen trifluoride ________________________ 1.
2.
3.
4.
5.
mono
di
tri
tetra
penta
6. hexa
7. hepta
8. octa
9. nona
10. deca
silicon dioxide _________________ Element Cu Hg Au Fe Co Ni Pb Sn Mn Group 15 (N, P, As, Sb, Bi) S TABLE 1: Elements with Two Positive Valences Valence(s) +1 +2 +1 +2 +1 +3 +2 +3 +2 +3 +2 +3 +2 +4 +2 +4 +2 +4 +3 +5 IUPAC System copper (I) copper (II) mercury (I) mercury (II) gold (I) gold (III) iron (II) iron (III) cobalt (II) cobalt (III) nickel (II) nickel (III) lead (II) lead (IV) tin (II) tin (IV) manganese (II) manganese (IV) phosphorus (III) phosphorus (V) ­ous / ­ic names cuprous cupric mercurous mercuric aurous auric ferrous ferric cobaltous cobaltic +4 +6 sulfur (IV) sulfur (VI) sulfurous sulfuric plumbous plumbic stannous stannic phosphorous phosphoric NOTE: These transition metals have single valences: Silver (Ag): +1 Therefore no Roman numeral is required. Zinc (Zn): +2 3) BINARY ACIDS • acids are compounds that release hydrogen ions (H+) • binary acids contain 2 elements; first is hydrogen • dissolved in water (aq = aqueous) Name: hydro_________________ic acid hydrofluoric acid _____________ hydrosulfuric acid _____________ HCl (g) _________________________________________ HCl (aq) _________________________________________ 4) BASES •
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•
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contain the polyatomic ion hydroxide (OH‐) a polyatomic ion is a group of atoms with a net charge these ions are treated as if they consist of 1 element Lewis structure of hydroxide: sodium hydroxide _______________ lead (IV) hydroxide _____________ Be(OH)2 ___________________________________________ Fe(OH)2 ___________________________________________ 5) Elements •
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Noble Gases are always monoatomic (1 atom in formula) other gases / halogens are diatomic (2 atoms bonded) metals are always monoatomic in their elemental form helium gas _____________ Fe (s) ___________________ nitrogen gas _________________ I2 (s) _________________________ SCH3U
Naming Simple Binary Compounds
PART A: Name the following compounds.
e.g. NaF = sodium fluoride
1. NaCl _________________________
2. CaCl2 _____________________________
3. CaO _________________________
4. MgBr2 ____________________________
5. CaS _________________________
6. Ag2S ______________________________
7. H2O _________________________
8. AlI3 _______________________________
9. Na2O ________________________
10. Al4C3 ____________________________
11. Mg3N2 ______________________
12. H2S ______________________________
13. AlN _________________________
14. SiC ______________________________
15. Al2O3 _______________________
16. KBr ______________________________
PART B: Write the chemical formula for the following compounds.
e.g. beryllium nitride = Be3N2
1. aluminum carbide ____________
2. hydrogen oxide _____________________
3. aluminum oxide ______________
4. silver sulfide * ______________________
5. silicon carbide ________________
6. calcium chloride ____________________
7. sodium chloride _______________
8. sodium oxide _______________________
9. magnesium bromide ___________
10. calcium sulfide ____________________
11. hydrogen sulfide _____________
12. magnesium nitride ________________
13. aluminum iodide _____________
14. calcium oxide _____________________
15. aluminum nitride ____________
16 sodium hydride ____________________
* Silver has a valence of +1.
SCH3U1
Determining Valences
Valence numbers describe an element’s bonding capacity. Positive valences
indicate the element tends to give up electrons (e,g. metals) while negative valences
indicate elements that tend to gain electrons. Generally, valences tell us the charge
of the elements in an ionic bond or the number of shared electrons in a covalent
bond.
State the valence of each element in the following compounds. If the metal is
multivalent (i.e. can have more than one possible charge), deduce the charge based
on the valence of the non-metal.
e.g. Fe2O3
Fe is +3 and O is -2.
HBr
NaF
HF
SnCl2
H 2O
Sb2O3
NH3
Na2S
N2 O 3
PbS
CH4
PbO2
SiCl4
MgS
CO2
ZnI2
PCl3
CaBr2
PCl5
BaO
AsCl3
Al2O3
AsCl5
MnCl2
HI
SO2
AgI
SO3
Cu2O
BCl3
CuO
SbCl5
Hg2O
SbCl3
HgI2
LiF
SnF4
BeI2
KI
NiBr2
FeO
H2 S
SCH3U1
Nomenclature of Variable Valence Binary Compounds
Write the chemical formula or the chemical name for each of the following using the
system indicated.
PART A: The IUPAC Method
1. PbO ________________________
2. As2S5 _____________________________
3. Fe2O3 _______________________
4. CuI2 ______________________________
5. SnO _________________________
6. SbCl2 _____________________________
7. P2O3 _________________________
8. MnO2 _____________________________
9. mercury (I) chloride ____________
10. iron (III) oxide ________________
11. antimony (III) iodide __________
12. phosphorus (V) oxide __________
13 tin (II) oxide __________________
14. copper (II) bromide ____________
PART B: The –ous / -ic Method
1. SnCl4 _________________________
2. Sb2O3 _____________________________
3. CuBr2 _________________________ 4. FeBr2 _____________________________
5. Fe2S3 _________________________
6. HgI ______________________________
7. mercurous chloride ____________
8. antimonous chloride _____________
9. phosphoric sulfide _____________
10. ferric oxide ____________________
11. phosphorous oxide ____________
12. mercuric chloride ______________
13. stannous bromide _____________
14. cuprous iodide _________________
15. phosphoric oxide ______________
16. arsenic sulfide _________________
17. stannic fluoride _______________
17. ferrous oxide ___________________
PART C: The Greek Prefix Method
1. SO3 ___________________________ 2. As2S5 ________________________________
3. PbO ___________________________ 4. N2O3 _________________________________
5. carbon dioxide __________________
6. manganese dioxide _______________
7. phosphorus trichloride ___________
8. carbon monoxide _________________
9. diarsenic trioxide _______________
10. lead dioxide ____________________
11. copper monochloride ____________
12. sulfur trioxide __________________
13. carbon tetrachloride _____________
14. diphosphorus pentoxide _________
Binary Compounds (all types)
Write the chemical formula for each compound.
1. sulfur (VI) fluoride __________
11. manganese (VII) oxide __________
2. mercuric iodide __________
12. manganese monoxide __________
3. tin (IV) chloride __________
13. stannous nitride __________
4. potassium nitride __________
14. dinitrogen monoxide __________
5. beryllium iodide __________
15. boron sulfide __________
6. rubidium phosphide __________
16. antimony (III) fluoride __________
7. iron (III) oxide __________
17. plumbous sulphide __________
8. sulphur (VI) oxide __________
18. sulphur hexafluoride __________
9. sulphurous oxide __________
19. copper (II) oxide __________
10. diarsenic trioxide __________
20. xenon difluoride __________
Write the name of the following compounds using the system indicated.
1. F2O (Greek Prefix)) ________________________________
2. AuCl3 (IUPAC) ____________________________________
3. N2Cl4 (Greek Prefix) ________________________________
4. HCl (simple binary) _________________________________
6. Al4C3 (simple binary) ________________________________
7. CaC2 (Greek Prefix) _________________________________
8. Cu2S (-ous/-ic) _______________________________________
Write three possible names for the following compounds.
1. Fe2O3
______________________________________
______________________________________
______________________________________
2. SF6
______________________________________
_______________________________________
_______________________________________
SCH3U1
Binary Compounds, Binary Acids, Bases and Gases
A. Name these compounds using the IUPAC method:
1. CuCl __________________________ 4. Fe2O3 __________________________
2. SnBr2 __________________________ 5. As2S5 __________________________
3. SO2 __________________________
6. MnO2 __________________________
B. Name these compounds using the –ous/-ic method:
1. HgCl2 __________________________ 4. FeCl3 __________________________
2. Sb2O3 __________________________ 5. CuBr __________________________
3. FeO __________________________
6. As3N5 __________________________
C. Name these compounds using the Greek Prefix method:
1. PbO2 __________________________ 4. HgO __________________________
2. As2S3 __________________________
5. SI5 __________________________
3. SO3 __________________________
6. CCl4 __________________________
D. Write the correct formula for each compound:
1. mercuric bromide ______________
9. ferrous oxide ______________
2. tin (II) iodide ______________
10. calcium hydroxide ______________
3. diantimony pentoxide _____________ 11. hydroiodic acid ______________
4. magnesium nitride ______________ 12. silver sulfide ______________
5. oxygen gas ______________
13. hydrosulfuric acid ______________
6. zinc hydroxide ______________
14. barium sulfide ______________
7. tin (II) oxide ______________
15. carbon monoxide ______________
8. aluminum hydroxide _____________ 16. hydrophosphoric acid ___________
E. Write an acceptable systematic name beside these archaic names.
1. lime (CaO) ___________________________________________
2. antimony black (Sb2S3) _________________________________
3. slaked lime (Ca(OH)2) _________________________________
Binary Compounds, Binary, Bases and Gases (continued)
Note: aq = aqueous state (dissolved in water); g = gas state; l = liquid state
1. Give the chemical formula for each compound.
sodium oxide _____________________
aluminum carbide _________________
potassium iodide __________________ mercuric oxide __________________
silicon oxide __________________ ____
iron (III) hydroxide _________________
phosphorous iodide ________________ magnesium nitride _________________
calcium bromide __________________
beryllium hydroxide ________________
sodium hydride ___________________
hydrogen oxide __________________
hydroiodic acid ___________________
hydrofluoric acid________________ (aq)
ferrous sulphide __________________
hydrogen fluoride gas ____________ (g)
hydrosulfuric acid _________________ mercury (I) chloride _________________
iron (II) hydroxide _________________ magnesium hydroxide ______________
arsenous fluoride __________________ nitrogen gas __________________ (g)
antimony (V) sulfide _______________ helium gas __________________ (g)
2, Name these compounds.
SO3 ______________________________ As2S3 ______________________________
AgO _____________________________
HI (g) ______________________________
Ba(OH)2 _________________________
HBr (aq) ___________________________
SnO _____________________________
Ag2S ______________________________
SbCl5 ____________________________
CuOH _____________________________
Xe (g) ____________________________
Br2 (l) _____________________________
CoCl2 ____________________________
H2 (g) __________________________
HBr (g) __________________________
SO2 _______________________________
PbOH)4 ______________________________________________
SeCl6 ________________________________________________
AgOH ________________________________________________