Chemical Nomenclature: The Greek Prefix System
Rev. 021712
Part three - Binary compounds of two nonmetals
Simple binary compounds composed of two nonmetals do not use the Stock system. Instead,
Greek prefixes are used to indicate the number of each element.
To use the Greek prefix system…
1. Write the name of the first element and include a Greek prefix to indicate the number of
atoms of that element.
2. Write the name of the second element with the name modified to end in "-ide", and include
a Greek prefix to indicate the number of atoms of that element.
Greek prefixes
mono 1
di
2
tri
3
tetra 4
penta 5
hexa
hepta
octa
nona
deca
6
7
8
9
10
Examples
Write the name, given the formula:
CO2 → carbon dioxide
SO3 → sulfur trioxide
CCl4 → carbon tetrachloride
N2O3 → dinitrogen trioxide
P4O10 → tetraphosphorous decoxide
Write the formula, given the name:
silicon dioxide → SiO2
dichlorine oxide → Cl2O
phosphorous pentachloride → PCl5
dinitrogen pentoxide → N2O5
arsenic tribromide → AsBr3
Note: When a prefix ending in "a" or "o"
precedes a vowel, the final "a" or "o" is dropped.
For example, drop the "o" in mono in "carbon
monoxide". Drop the "a" in tetra in "dinitrogen
tetroxide".
Write the name of each compound.
1.
PCl3
2.
CO
3.
BF3
4.
SCl6
5.
XeF4
6.
AsBr5
7.
N2O5
8.
SO2
9.
N2O
10. KrF2
Write the formula of each compound.
1.
sulfur trioxide
2.
Iodine heptafluoride
3.
dichloroine trioxide
4.
arsenic triiodide
5.
diphosphorous trioxide
6.
nitrogen trichloride
7.
selenium monoxide
8.
silicon tetrafluoride
9.
chlorine pentafluoride
10. xenon hexafluoride
Review: Balance the following chemical equations
O2(g) → SO3(g)
1.
S(s) +
2.
PH3(g) +
3.
C2H6(g) +
O2(g) →
4.
Cl2O(g) +
HF(g) → ClF(g) + H2O(l)
5.
As2O5(s) + H2O(l) → H3AsO4(aq)
O2(g) →
H3PO4(l)
CO2(g) +
H2O(l)
Answers
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
PCl3 → phosphorous trichloride
CO → carbon monoxide
BF3 → boron trifluoride
SCl6 → sulfur hexachloride
XeF4 → xenon tetrafluoride
AsBr5 → arsenic pentabromide
N2O5 → dinitrogen pentoxide
SO2 → sulfur dioxide
N2O → dinitrogen oxide
KrF2 → krypton difluoride
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
sulfur trioxide → SO3
Iodine heptafluoride → IF7
dichloroine trioxide → Cl2O3
arsenic triiodide → AsI3
diphosphorous trioxide → P2O3
nitrogen trichloride → NCl3
selenium monoxide → SeO
silicon tetrafluoride → SiF4
chlorine pentafluoride → ClF5
xenon hexafluoride → XeF6
1.
2.
3.
4.
5.
2S(s) + 3O2(g) → 2SO3(g)
PH3(g) + 2O2(g) → H3PO4(l)
2C2H6(g) + 5O2(g) → 4CO2(g) + 6H2O(l)
Cl2O(g) + 2HF(g) → 2ClF(g) + H2O(l)
As2O5(s) + 3H2O(l) → 2H3AsO4(aq)