writing formulas and naming compounds when compounds form, the net charge always equals zero. the...
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Writing Formulas and Naming Compounds
When compounds form, the net charge always equalszero. The number of + always equals the number of -.
3+3-
Lets picture what happens• Na+ + Cl- are attracted to
each other.
• Na+ and O2- are attracted to each other.
Na+
Na+
Cl-
O2-Na+
NaCl
Na2O
Your turn: Use the following ions to make as many compounds as you can. You may use your ion sheet.
• potassium• magnesium• Gallium• Lithium
• chloride• oxide• hydroxide• phosphide• phosphate
• Cl1-
• O2-
• (OH)1-
• P3-
• PO43-
Li3PGaPMg3P2K3PP3-
Ga(OH)3Mg(OH)2KOH(OH)1-
Li2OGa2O3O2-
KClCl1-
Li1+Ga3+Mg2+K+
MgCl2 GaCl3 LiClK 2O MgO
LiOH
K+ Mg2
+
Ga3+ Li+
Cl-
O2-
OH-
P3-
Potassiumchloride
Potassiumoxide
Potassiumhydroxide
Potassiumphosphide
Magnesiumchloride
Magnesiumoxide
Magnesiumhydroxide
Magnesiumphosphide
galliumphosphide
Oxidation number
• The charge on a monatomic ion is called the oxidation number.
• An ion with more than one atom, has a different oxidation number on each atom, so the sum of the oxidation numbers equals the charge of the ion.
• Your ion sheet lists some common oxidation numbers for metals .
Reading Isotopes
S32
16
2-
Mass number
Charge or oxidation number
atomic number = number of
protons
Reading Isotopes
F19
9
1-
Mass number
Charge or oxidation number
atomic number = number of
protons
What is the oxidation numbers of sulfur in this compound?
CaSO4
2+ 4 of 2- = -8
?
0 = 2 - 8 + ?? = 6
What is the oxidation numbers of phosphorous in this compound?
Na3 PO4
3 sets of 1+
4 of 2- = -8
?
0 = 3 - 8 + ?? = 5
• Write the formula for the following compounds:– calcium
chloride– sodium
cyanide– magnesium
oxide
CaCl2
Na CN
Mg
MAKE SURE THECHARGES AREBALANCED!
O
• Write the formula for the following compounds:– silver and
fluorine– nickel (II) and
sulfur– chromium (III)
and bromine
Ag F
Ni S
Cr
MAKE SURE THECHARGES AREBALANCED!
Br3
4. Write formulas for the following.
• barium sulfate
• barium sulfide
• magnesium phosphate
• strontium bromide
• chromium (III) acetate
• Ba2+
• SO42-
• S2-
• Mg2+
• PO43-
• Sr2+
• Br1-
• Cr3+
• C2H3O21-
BaSO4
BaS
Mg3(PO4)2
…….
mass number = number of protons + number of neutrons
atomic number = number of protons
# neutrons = mass # - atomic #
# electrons = # protons
Explain lead-207’s parts
Pb207
82
mass number
atomic number
Naming Binary inorganic compounds.
Al2S3
Aluminum Al3+
SulfideS2-
K3P
PotassiumK+
PhosphideP3-
The charges not needed for naming most compoundsThe charges are only needed for writing chemical formulas.
Naming Binary inorganic compounds containing transition metals.
Cr2S3
chromium (III)Cr3+
SulfideS2-
Cu3P
copper (I)Cu+
PhosphideP3-
The charges ARE needed for naming these compoundsThe charges are also needed for writing chemical formulas.
To name covalent compounds
• Covalent compounds are composed of two or more nonmetals which share electrons. (Some metalloids are covalently bonded as well).
• USE PREFIXES mono = 1 penta = 5di = 2 hexa = 6tri = 3 hepta = 7tetra = 4 octa = 8
prefix if not mono-nameof less electronegative atom, prefix of second atom– ending ide
Naming covalent compounds
• CO2
• CO
• P2O5
mono = 1 penta = 5di = 2 hexa = 6tri = 3 hepta = 7tetra = 4 octa = 8
• carbon dioxide• carbon monoxide• diphosphorous
pentoxideTry SF6
sulfur hexafluoride
Naming Organic Compounds
• Organic compounds have one or more carbons, surrounded with hydrogens.
• They may have double or triple bonds, and may include oxygen, or other atoms.
• They are named by counting the “carbon backbone” and applying a prefix
• “Functional Groups” provide the rest of the name.
meth = 1eth = 2prop = 3but = 4pent = 5hex = 6hept = 7oct = 8non = 9…
Naming Organic Compounds
• Butane = 4 carbons
• CH3CH2CH2CH3
• Heptane = 7 carbons
• CH3CH2CH2CH2CH2CH2CH3
• Octane = 8 carbons
• CH3CH2CH2CH2CH2CH2CH2CH3
meth = 1eth = 2prop = 3but = 4pent = 5hex = 6hept = 7oct = 8non = 9…