Review: Naming Covalent (Molecular) Compounds
Covalent compounds
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
involve bonding between non-metals
involve sharing (not transfer) of electrons
atoms bonded covalently form molecules
To name covalent (non-metal-nonmetal) compounds:
1. Name the first element in the compound using the name as found on the
periodic table.
2. Name the second element with an –ide ending.
3. Use numerical prefixes to show how many of each atom is present in the
molecule.
*mono is omitted for the name of the first element
Prefix
mono
di
tri
tetra
penta
hexa
hepta
octa
nona
deca
Number of atoms
1
2
3
4
5
6
7
8
9
10
Examples:
P2S5
diphosphorus pentasulfide
CCl4
carbon tetrachloride
Si2Br6
disilicon hexabromide
SI4
sulfur tetraiodide
Some exceptions:
1. Diatomics (elements that always exist as covalently-bonded pairs when they are in their pure form): there
are seven: H2 O2 F2 Br2 I2 N2 Cl2
These diatomics are simply given their elemental name, ex: O2 is called oxygen
2. Very common molecules are generally referred to by their common names:
Ex:
H2O
water
NH3
ammonia
Name the following compounds
1. SO2
______________________________________________________
2. CO
______________________________________________________
3. ClO2
______________________________________________________
4. N2O
______________________________________________________
5. P2O5
______________________________________________________
6. CBr4
______________________________________________________
7. N2S5
______________________________________________________
8. N2O5
______________________________________________________
9. BF3
______________________________________________________
10. SiCl4
______________________________________________________
11. IF7
______________________________________________________
12. P4O10
______________________________________________________
13. PO3
______________________________________________________
14. BrCl3
______________________________________________________
15. P2O4
______________________________________________________
16. NF4
______________________________________________________
17. S4N4
______________________________________________________
18. NF3
______________________________________________________
19. NO2
______________________________________________________
20. Cl2O7
______________________________________________________
Write the formulas for the following compounds:
1. carbon dioxide
________________________
2. nitrogen monoxide
________________________
3. nitrogen dioxide
________________________
4. sulfur trioxide
________________________
5. tetraphosphorus decoxide
________________________
6. tetraphosphorus hexoxide
________________________
7. hydrogen monochloride
________________________
8. dihydrogen monoxide
________________________
9. nitrogen trichloride
________________________
10. carbon disulfide
________________________
11. disilicon hexabromide
________________________
12. tetranitrogen tetrasulfide
________________________
13. carbon monoxide
________________________
14. dinitrogen pentoxide
________________________
15. water
________________________
16. ammonia
________________________
17. phosphorus pentachloride
________________________
18. carbon tetrachloride
________________________
19. diselenium dichloride
________________________
20. dinitrogen tetroxide
________________________
Naming Acids
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
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Acids are a special group of substances, they are compounds of non-metals but they
form ions in solution.
Acids can be recognized by the fact that their chemical formula generally begins with H
Because acids are a unique group, they have different naming rules:
Acid
Example
Anion
Clchloride
NO2nitrite
NO3nitrate
HCl
HNO2
HNO3
Anion
ending
How To Name it
Name
-ide
hydro(stem)ic acid
hydrochloric acid
-ite
(stem)ous acid
nitrous acid
-ate
(stem)ic acid
nitric acid
**Two stem ‘exceptions’:
S
sulfur
– the stem is ‘sulfur’
ex. sulfuric acid
P phosphorus – the stem is ‘phosphor’
ex. phosphoric acid
Examples: Use the rules to name the following:
1. HBr
2. HClO4
3. H2S
hydrobromic acid
perchloric acid
hydrosulfuric acid
Complete the table with the missing acid names or formulas.
Formula
1. HNO3
2.
3. H2SO3
4. H2C2H3O2
5.
6. H2S
7.
8.
9.
10.
Name
sulfuric acid
phosphoric acid
carbonic acid
hypochlorous acid
hydrosulfuric acid
hydrofluoric acid
So…let’s put this all together!!
When naming or writing chemical formulas, first determine what type of compound you are
dealing with:
Ionic
metal+non-metal/polyatomic
Covalent:
non-metal+non-metal
Acid:
formula begins with H
Type of Chemical Bonds
Classify the following compounds as ionic, covalent, or acids.
1. CaCl2
11. MgO
2. CO2
12. CuCl2
3. H2SO4
13. HCl
4. BaSO4
14. KI
5. K2O
15. NaOH
6. NaF
16. NO2
7. Na2CO3
17. AlPO4
8. CH4
18. FeCl3
9. SO3
19. P2O5
10. LiBr
20. N2O3
Naming Practice (all types of compounds)
Name the following compounds:
1. CaCO3
2. SCl6
3. PCl5
4. CaS
5. Cu2SO3
6. K3N
7. NH4NO3
8. Al(OH)3
9. HNO3 (aq)
10. HBr (aq)
11. N2O4
12. O2
13. Mg3N2
14. NF3
15. NH3
16. H2CO3 (aq)
17. CS2
18. H2S (aq)
19. AuCl3
20. KMnO4
Write the formulas of the following compounds:
1. potassium nitrate
2. iron (III) chloride
3. acetic acid
4. nitrous acid
5. nitrogen monoxide
6. zinc phosphate
7. hydrochloric acid
8. tin (IV) chloride
9. magnesium hydride
10. nickel (II) chlorate
11. diphosphorus pentoxide
12. ferric hydroxide
13. phosphoric acid
14. strontium phosphide
15. sulfur dioxide
16. aluminum oxide
17. zinc fluoride
18. carbon dioxide
19. mercury (II) sulfate
20. sulphuric acid