Science Academy

11/10/2016

Father of Chemistry
Antoine-Laurent de Lavoisier

11/10/2016

27/09/2015

GOOD MORNING EVERYONE

26/09/2015

Number of Atoms Prefix
1 mono
6 hexa
2 di
3 tri
4 tetra
5 penta
6 hexa
7 hepta
8 octa
9 non
a
10 deca

26/09/2015

Naming Binary Molecular
Compounds
Molecular compounds are formed from
the covalent bonding between non-
metallic elements. The nomenclature
for these compounds is described in
the following set of rules.
1. The more positive atom is written first
(the atom which is the furthest to the
left and to the bottom of the periodic
table)
2. The more negative second atom has
an "-ide" ending.
3. Each prefix indicates the number of
each atom present in the compound.
Number of Atoms Prefix Number of Atoms Prefix
1 mono 6 hexa
2 di 7 hepta
3 tri 8 octa
4 tetra 9 nona
5 penta 10 deca
Examples:
CO2 = carbon dioxide
P4S10 = tetraphosphorus decasulfide

26/09/2015

Naming Ionic Compounds
The outline below provides the rules
for naming ionic compounds:
Positive Ions
1. Monatomic cations (a single atom with
a positive charge) take the name of
the element plus the word "ion"
Examples:
Na+ = sodium ion
Zn+2 = zinc ion
2. If an element can form more than one
(1) positive ion, the charge is indicated
by the Roman numeral in parentheses
followed by the word "ion"
Examples:
Fe2+ = iron(II) ion
Fe3+ = iron (III) ion
Negative Ions
1. Monatomic anions (a single atom with
a negative charge) change their
ending to "-ide"
Examples:
O2- = oxide ion
Cl- = chloride ion
2. Oxoanions (negatively charged
polyatomic ions which contain O) end
in "-ate". However, if there is more
than one oxyanion for a specific
element then the endings are:
Two less oxygen than
the most common
starts with "hypo-"
and ends with "-ite"
One less oxygen
than the most
common ends
with "-ite"
THE MOST COMMON OXOANION ENDS
WITH "-ATE"
One more oxygen
than the most
common starts with
"per-" and ends with
"-ate"
ClO- = hypochlorite
ClO2- =
chlorite
NO2- = nitrite
SO32- =
sulfite
Most common
oxyanions with
four oxygens
SO42- =
sulfate
PO43- =
phosphate
CrO42- =
chromate
Most common
oxyanions with
three oxygens
NO3- = nitrate
ClO3- =
chlorate
CO32- =
carbonate
ClO4- = perchlorate
3. Polyatomic anions (a negatively
charged ion containing more than one
type of element) often add a hydrogen
atom; in this case, the anion's name
either adds "hydrogen-" or "bi-" to the
beginning
Example:
CO32- becomes HCO3-
"Carbonate" becomes either
"Hydrogen Carbonate" or
"Bicarbonate"
4. When combining cations and anions
into an ionic compound, you always
put the cation name first and then the
anion name (the molecular formulas
are also written in this order as well.)
Examples:
Na+ + Cl- --> NaCl
sodium + chloride --> sodium chloride
Cu2+ + SO42- -->CuSO4
copper(II) + sulfate --> copper(II)
sulfate
Al3+ + 3NO3- --> Al(NO3)3
aluminum + nitrate --> aluminum
nitrate

26/09/2015

Forming Ionic Compounds
Knowing the oxidation number of a
compound is very important when
discussing ionic compounds. Ionic
compounds are combinations of
positive and negative ions. They are
generally formed when nonmetals and
metals bond. To determine which
substance is formed, we must use the
charges of the ions involved. To make
a neutral molecule, the positive charge
of the cation (positively-charged ion)
must equal the negative charge of the
anion (negatively-charged ion). In
order to create a neutral charged
molecule, you must combine the
atoms in certain proportions. Scientists
use subscripts to identify how many of
each atom makes up the molecule. For
example, when combining magnesium
and nitrogen we know that the
magnesium ion has a "+2" charge and
the nitrogen ion has a "-3" charge. To
cancel these charges, we must have
three magnesium atoms for every two
nitrogen atoms:
3Mg2+ + 2N3- --> Mg3N2
Knowledge of the charges of ions is
crucial to knowing the formulas of the
compounds formed.
alkalis (1st column elements) form
"+1" ions such as Na+ and Li+
alkaline earth metals (2nd column
elements) form "2+" ions such as
Mg2+ and Ba2+
halogens (7th column elements) form
"-1" ions such as Cl- and I-
Other common ions are listed in the
table below:
Positive ions (cations) Negative ions (anions)
1+ 1-
ammonium (NH4+) acetate (C2H3O2-)
copper(I) (Cu+) azide (N3-)
hydrogen (H+) chlorate (ClO3-)
silver (Ag+) cyanide (CN-)
dihydrogen phosphate (H2PO4-)
2+ hydride (H-)
cadmium (Cd2+) bicarbonate (HCO3-)
cobalt(II) (Co2+) hydroxide (OH-)
copper(II) (Cu2+) nitrate (NO3-)
iron (Fe2+) nitrite (NO2-)
lead (Pb2+) perchlorate (ClO4-)
manganese(II) (Mn2+) permanganate (MnO4-)
mercury(I) (Hg22+) thiocyanate(SCN-)
mercury(II) (Hg2+)
nickel (Ni2+) 2-
tin (Sn2+) carbonate (CO32-)
zinc (Zn2+) chromate (CrO42-)
dichromate (Cr2O72-)
3+ hydrogen phosphate (HPO42-)
aluminum (Al3+) oxide (O2-)
chromium(III) (Cr3+) peroxide (O22-)
iron(III) (Fe3+) sulfate (SO42-)
sulfide (S2-)
sulfite (SO32-)
3-
nitride (N3-)
phosphate (PO43-)
phosphide (P3-)

26/09/2015

Oxidation and Reduction

When forming compounds, it is important to know something about the way atoms will react with each other.
One of the most important manners in which atoms and/or molecules react with each other is the oxidation/
reduction reaction. Oxidation/Reduction reactions are the processes of losing and gaining electrons
respectively. Just remember, "LEO the lion says GER:" Lose Electrons Oxidation, Gain Electrons Reduction.
Oxidation numbers are assigned to atoms and compounds as a way