Nanjiba Kabir
April 4, 2014
SCH3U1-07
Dr.Baczynsky
Review for Nomenclature Test
 CROSS-OVER RULE FOR WRITING FORMULAS
1.
2.
3.
4.
Write down the symbol of the elements in the order given in the name.
Write the valences above the elements symbol
Cross-over valences
Simplify the formula by the highest common multiple of the valence, if needed.
 BINARY COMPOUNDS
Rules for Binary Ionic Compounds:
1. The name of the binary compound always ends in “ide”.
2. The first element may have more than one valence and if it does this must be indicated in the
name.
3. If the valence of the first element is not indicated in the name, their valence value is determined
by their group on the Periodic table.
There are two types of Binary ionic compounds:
 Binary Compounds where first element has 1 valence only
Ex: Sodium Oxide
Na2O
 Binary Compounds with Multivalent Elements (MUST MEMORIZE THE CHART GIVEN)
Ex: Iron (III) chloride
FeCl3
*Be familiar with the stock (IUPAC or Roman Numeral) or Classical (“ous” and “ic”) system
 H O F Br I N Cl and S P
Elements that are not written in a single entity
 COMMON RADICALS OR POLYATOMIC IONS
They are a group of atoms that are treated as a single entity when writing formulas and names.
A chart is given to memorize the polyatomic ions and their valences.
Also if more than one of the radical is required in the formula, brackets are needed around the radical
with the subscript outside the bracket.
Ex: Ferrous Oxide
Fe(OH)2
Nanjiba Kabir
April 4, 2014
SCH3U1-07
Dr.Baczynsky
 ACIDS
1. Binary Acid – small but common group of acids
Rules:
1. All have the prefix “hydro” and end with “ic”
2. Must contain hydrogen as the first element
3. Normal cross-over-rule to determine the formula
4. Made by dissolving the gas in water and must be indicated by using (aq) behind the formula
5. Have no oxygen in their formula
Ex: hydrochloric acid
HCl(aq)
2. Oxy acids – contain H, O and another non-metal element
Rules:
1. The name of the acid ends in “ic”
2. The name of the associated radical ends in “ate”
3. The valence value of the associated radical is equal to the number of acids hydrogens in the acid
Ex. Chloric acid
HClO3
*Oxy acid chart must be memorized.
3. Derived Oxy acids
-Acids from this group are derived from the parent oxy acids.
-In derived oxy acids, when oxygen atoms are added or removed from the parent acid, the # of
hydrogens on the acid and the valence of the associated radical remain the same as the parent.
Naming derived oxy acids and radicals
Type of Acid
Associated Radical
Parent Oxy Acid +1 O
Per____ic
Per___ate
Parent Oxy Acid
ic
ate
Parent Oxy Acid -1 O
ous
ite
Parent Oxy Acid -2 O
Hypo___ous
Hypo__ite
*Derived Oxy acid chart must be memorized
 SALTS – compounds that are formed when an acid and base neutralize each other
 ACID RADICALS & ACID SALTS
Oxy acids with multiple acidic hydrogens are able to lose the hydrogens
Notes:
a. Valence = # of hydrogen removed from the acid
b. Mono may be left off a monohydrogen acid radical
c. For oxy acids with 2 acidic hydeogens , the prefix “bi” can be used in the place of
monohydrogen
Nanjiba Kabir
April 4, 2014
SCH3U1-07
Dr.Baczynsky
 HYDRATES – crystals containing a given number of water molecules within their structure
Ex: chlorine octahydrate
Cl2 . 8 H2O
 PEROXIDES – Binary oxides, which contain extra oxygen atom
Rules:
1. Write the formula of the regular oxide
Na2O
2. Add on one extra oxygen atom
Na2O2
3. Do not at this stage simplify any of the subscripts
 THIO COMPOUNDS – when an oxygen atom has been replaced by a sulphur atom
Ex: potassium sulphate
K2SO4
potassium thiosulphate
K2S2O3
 MOLECULAR COMPOUNDS – contain 2 non-metals
-Use Greek prefixes to indicate the number of atoms of the element that take place in the
formula
Prefix in order from 1 to 10: mono, di, tri, tetra, penta, hexa, hepta, octa, nona, deca
Ex. CO – carbon monoxide
*prefixes are not used if the first element has 1 atom
MORE PRACTICE
http://chemistry.about.com/library/weekly/blcompnamequiz.htm
http://www.wiziq.com/online-tests/27457-naming-of-compounds-chemistry
http://www.sciencegeek.net/Chemistry/taters/Unit4BinaryNomenclature.htm
http://www.fernbank.edu/Chemistry/nomen.html
AGENDA
Complete all the practice sheets so you can be prepared for the Nomenclature Test on Monday
Complete the pre-lab questions for the Types of Chemical Reactions Lab for Tuesday