Nomenclature:
Type III and Acids
Elizabeth Sikora & Roxanne Schoen
Type III : Binary Covalent Compounds
• Binary covalent compounds are when two
non-metals form a chemical compound
Type III : Binary Covalent Compounds
• When naming the first element shown keeps its original name and only
uses a prefix when it is greater than one molecule. The second element
shown is named according to the anion name ending in –ide and always
uses prefixes.
• When finding formulas there is no criss-crossing of the charges, you tell
the number of molecules per element only by the prefix.
1=mono
2=di
3=tri
4=tetra
5=penta
6=hexa
7=hecta
8=octa
9=nona
10=deca
Type III : Binary Covalent Compounds
Example 1:
CO2 = Carbon Dioxide
• –Since both elements are nonmetals, you know it is a type III compound.
• –The first element, Carbon, is a single molecule so it has no prefix
• –The second element, Oxygen, is presented twice so the prefix di- is
added along with the anion ending –ide.
Acids
Acids are a compound containing the ionizable proton (H+)
When finding a formula for an acid, you must take the element or
poloytomic’s charge and criss-crossing it with (H+)
Polytomics with oxygen are named by taking the root of the polyotomic and
either dropping the –ate and putting in –ic or by dropping the –ite and
putting –ous.
Acids which do not contain oxygen are named by adding the prefix hydroto the root name of the element followed by the suffix –ic
Acids with Poloytomics containing
oxygen
• Example 1:
H2SO4 = sulfuric acid
–Sulfuric Acid is made by taking the polytomic sulfate (SO4-2) and crisscrossing the charge of H+1 the name is made by dropping the –ate and
adding –ic
• Example 2:
H2SO3 = sulfurous acid
–Sulfurous Acid is made by taking the polytomic sulfite (SO3-2) and crisscrossing the charge of H+1 the name is made by dropping the –ite and
adding –ic
Acids that do not contain oxygen
• Example 1:
H3P = Hydrophosphoric Acid
–Hydrophosphoric Acid is made by taking the element Phosphorous (P-3)
and combining it with Hydrogen (H+1) and criss-crossing the charges.
The name is made by using the root of phosphorous (phospor) and
adding the prefix hydro- and suffix -ic
Name the chemical compound:
HBr
Answer:
Hydrobromic acid
When hydrogen combined with Bromine, you add the hyrdo- and –ic
because it is a single element combined with Hydrogen
Give the formula for:
Phosphorous trioxide
Answer:
PO3
Since there is no prefix in front of phosphorus, it means it’s a single
molecule whereas oxygen has 3 molecules and is given the prefix -tri
Give the formula for:
Hydrocyanic Acid
Answer:
HCN
Since cyanide and hydrogen’s charges cancel out, there is only one
molecule of each.
Give the formula for:
Hydroiodic Acid
Answer:
HI
Since the hydrogen and iodine charges cancel each other out, you are just
left with the combination of the single molecules.
Name the chemical compoud:
S6F5
Answer:
Hexasulfur Pentafluoride
Since there are six sulfur molecules you give the prefix –hexa to sulfur.
Since there are five fluorine molecules you add the prefix –penta to the
name. Since it is the second element you also add the suffix –ide.
Name the chemical compound:
H2SO4
Answer:
Sulfuric Acid
When naming an acid with oxygen, you must use the root of the original
polyatomic sulfate (SO4-2) and drop the –ate ending and replace it with ic
Give the formula for:
Phosphorous Acid
Answer:
H3PO3
When combining H+1 and the polyatomic PO3+3 you must cross their
charges.
Give the formula for:
Dinitrogen hexoxide
Answer:
N2O6
The prefix –di on nitrogen means there are two nitrogen molecules and the
prefix hex on oxygen means there are six oxygen molecules
What is the proper name and formula for
the molecular compound:
3 sulfur and 5 chlorine atoms
Answer:
S3Cl5 and Trisulfur pentachloride
What is the proper name and formula for
the acid formed when you combine:
hydrogen and nitrate
Answer:
HNO3 and Nitric Acid
Key Points to Remember:
• Type III:
– 2 nonmetals, no crossing, use prefixes.
• Acids:
– Cross charges
– Polyotomics with oxygen: ate  ic, ite  ous
– Single elements: hydro + root of element + ic
Biblography
• http://nobel.scas.bcit.ca/chem0010/unit4/4.3.
2_property_nonmetals.htm (nonmetal
periodic table picture)