Ions - Clark College

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Transcript Ions - Clark College

Ions
Ions: A charged particle formed when a neutral
atom or group of atoms gain or lose one or
more electrons.
Example
Na  Na+ + eF + e-  F1
Cations
Mg  Mg2+ + 2eAl  Al3+ + 3eCation: A positively-charged ion. One or more
electrons are lost from a neutral atom
 oxidation
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Anions
I + e -  IO + 2e-  O2S + 2e-  S2Anion: A negatively-charged ion. Electrons are
gained by a neutral atom
 reduction
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Ions
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Ion charges can be predicted from the Periodic Table
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Main Group metal (IA-IVA) ion-charges correspond to
group number
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Main Group non-metal (IIIA-VIIIA) ion-charges
correspond to (group# - 8)
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Sodium (Na) in IA  +1
Fluorine (F) in VIIA  (7-8) = -1
All this has to do with electron configuration
See website as well:
http://web.clark.edu/aaliabadi/phSC106_ions%20shee
t.htm
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Compounds That Contain
Ions
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Require metal and non-metal
Form ionic bonds
Called an ionic compound
Characteristic Properties
1. Very high melting points
2. Conduct an electric current when melted or
when dissolved in water
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Ionic compound
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The number of cations and anions must have a net charge of
zero.
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Compounds that Contain
Ions
Writing Formulas for Ionic Compounds
Give the formulas for the compounds that contain the following
pairs of ions:
(a) K and I
(b) Mg and N
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Naming Ionic Compounds
1. The cation is always named first and the
anion second.
2. The cation takes its name from the name of
the element.
3. The anion is named by taking the first part of
the element name and adding –ide.
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Naming Ionic Compounds
Name the following Type I
compounds
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NaCl
RaBr2
Rb2O
AlI3
K3N
Cs4Si
Give the chemical formula for the
following Type I compounds
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Strontium phosphide
Calcium fluoride
Beryllium carbide
Lithium hydride
Barium sulfide
Magnesium telluride
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Naming Ionic Compounds
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Type II compounds need to be identified by a Roman numeral
 (I), (IV), etc.
Represents oxidation state of cation
Not how many cations are present in compound!
Example: NaCl  sodium (I) chloride is INCORRECT
Example: SnCl4  tin (IV) chloride is correct
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Naming Ionic Compounds
Type II Ionic Compounds
FeCl2 and FeCl3
PbO and PbO2
MnS and Mn2S7
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A Mixed Bag
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PbBr2 and PbBr4
Aluminum arsenide
FeS and Fe2S3
Thallium (III) boride
Mercury (II) carbide
Na2S
CoCl3
Cerium (IV) phosphide
ScF3
Gold (I) selenide
Vanadium (V) telluride
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Naming Compounds that
Contain Polyatomic Ions
Polyatomic Ion: An ion that contains more than one atom. They
are charged entities composed of several atoms bound
together.
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Consult my website for the list:
http://web.clark.edu/aaliabadi/phSC106_ions%
20sheet.htm
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Caveat
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Parenthesis required if more than one
polyatomic ion present
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Ca(ClO)2 is correct
Ca(I)2 is INCORRECT
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Naming Compounds that
Contain Polyatomic Ions
Name or provide the chemical formula for each of the following
compounds:
(a) Ca(OH)2
(e) Co(ClO)2
(b) Sodium phosphate
(f) platinum (IV) bicarbonate
(c) KMnO4
(g) Cu(NO2)2
(d) Ammonium nitrate
(h) nickel (III) oxide
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Naming Compounds that
Contain Polyatomic Ions
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Name or provide each of the following compounds:
(a) calcium carbonate
(e) MoO
(b) BaSO4
(f) Iridium (VII) acetate
(c) CsClO
(g) ZnCl2
(d) Zirconium sulfite
(h) lithium cyanide
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Naming Acids
Acids: A substance that yields hydrogen ions
(protons, H+) when dissolved in water.
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HCl(aq)  H+(aq) + Cl-(aq)
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H3PO4(aq)  3H+(aq) + PO43-(aq)
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Rules for naming acids
If the formula does not contain oxygen the prefix of the acid
is hydro and the suffix –ic is attached to the root name for
the element.
Ex: HCl = hydrochloric acid, H2S = hydrosulfuric acid
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When the anion contains oxygen, the acid name is formed
from the anion name. The suffix –ic or –ous is added.
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When the anion ends in –ate, the suffix –ic is used.
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H2CO3 = carbonic acid
When the anion ends in –ite, the suffix –ous is used.
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H2SO3 = sulfurous acid
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Naming Compounds that Contain
Only Nonmetals: Type III
Compounds containing only nonmetals:
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Form covalent bonds
share electrons
Rules for Naming Type III Binary Compounds
1. The first element in the formula is named first, and the full
element name is used.
2. The second element is named as though it were an anion.
3. Prefixes are used to denote the numbers of atoms present.
4. The prefix mono- is never used for naming the first element.
5. Drop the “a” when it is followed by an “o”
 Tetraoxide should be tetroxide
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Naming Compounds that Contain
Only Nonmetals: Type III
Prefixes Used to Indicate Numbers in Chemical Names
Prefix
Number Indicated
mono1
di2
tri3
tetra4
penta5
hexa6
hepta7
octa8
nona9
deca10
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Practice
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CCl4
Silicon dioxide
NO2
Sulfur trioxide
P2O5
Iodine pentafluoride
Dinitrogen tetroxide
SeI2
Xenon hexafluoride
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The Name Game
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Extra credit opportunity
Mix-and-match
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