Chapter 7- Chemical Formulas and Chemical Compounds
Download
Report
Transcript Chapter 7- Chemical Formulas and Chemical Compounds
Chapter 7- Chemical
Formulas and Chemical
Compounds
Ban Dihydrogen Monoxide!
Colorless, odorless, tasteless
Kills uncounted thousands of people every year.
Most deaths caused by accidental inhalation
Prolonged exposure to its solid form causes severe
tissue damage.
Symptoms of ingestion can include
excessive sweating and urination,
a bloated feeling,
nausea,
vomiting
body electrolyte imbalance.
For those who have become dependent, withdrawal
means certain death.
Ban Dihydrogen Monoxide!
Also known as hydroxl acid
Major component of acid rain
Contributes to the "greenhouse effect."
May cause severe burns.
Contributes to the erosion of our natural landscape.
Accelerates corrosion and rusting of many metals.
May cause electrical failures and decreased
effectiveness of automobile brakes.
Been found in excised tumors of terminal cancer
patients.
Is now an ingredient in most foods and beverages
Ban Dihydrogen Monoxide!
Based on the evidence presented in the
previous two slides, do you support the
banning of dihydrogen monoxide?
Write at least two sentences stating your
reasoning.
Please sign the petition!
What is Dihydrogen Monoxide?
Chemical Formulas
Indicate the relative number of atoms or
ions of each kind in a chemical compound
8 C atoms
C8H18
1 Mg2+ ion
MgCl2
1 Ca2+ ion
Ca(OH)2
18 H atoms
2 Cl- ions
2 OH- ions
Monatomic Ions
Ions formed from a single atom
Usually have noble gas configurations
That’s how we determine its charge
Example:
Li: 1s22s1
Li+: 1s2 or [He]
Table on p.221 on monatomic ions
Naming Monatomic Cations
Use the element’s name!
Yes, it’s that simple!
Example:
Cs+ = cesium
Al3+ = aluminum
Naming Monatomic Anions
Drop the ending of the element’s name
Add the ending –ide
Examples:
Cl- = chloride
N3- = nitride
Naming Monatomic Ions
K+
S2 Rb+
O2 I Ba2+
Cu+
potassium
sulfide
rubidium
oxide
iodide
barium
copper
Binary Ionic Compounds
Compounds composed of two ions
Total numbers of positive charges and
negative charges must be equal
Examples:
NaCl
KBr
CaF2
Writing Binary Ionic Compounds
Write the symbols for the ions side by
side. Write the cation first.
Al3+ O2
Cross over the charges to use as the
subscript for the other ion.
Al3+ O2Al2 O3
Writing Binary Ionic Compounds
Check the subscripts and divide them to
give the smallest whole number ratio of
ions.
Al2O3
Write the formula!
Al2O3
Writing Binary Ionic Compounds
Zinc iodide
Barium fluoride
Lithium oxide
Calcium oxide
Magnesium bromide
ZnI2
BaF2
Li2O
CaO
MgBr2
Naming Binary Ionic Compounds
Give name of cation first
Then name the anion
Al2O3
Name of cation: aluminum
Name of anion: oxide
Name of compound: aluminum oxide
Naming Binary Ionic Compounds
BaI2
ZnF2
K2O
MgO
CaBr2
Barium iodide
Zinc fluoride
Potassium oxide
Magnesium oxide
Calcium bromide
Cations With Different Charges
Some elements form two or more cations
with different charges
Fe2+ and Fe3+
Iron (II) and Iron (III)
Naming compounds
FeO and Fe2O3
Iron (II) oxide and Iron (III) oxide
Name the Following Compounds
CuO
CoF3
SnI4
FeS
Copper (II) oxide
Cobalt (III) fluoride
Tin (IV) iodide
Iron (II) sulfide
Quiz- Name the Following
Compounds
1.
2.
3.
4.
5.
K2S
AgBr
Na2O
FeCl2
BaS
6.
7.
8.
9.
10.
Lithium fluoride
Silver iodide
Iron (III) oxide
Magnesium iodide
Gold chloride
Polyatomic Ions
Ions that contain two or more atoms
Most are negatively charged
List of polyatomic ions is on handout
**MEMORIZE THEM!!!**
Examples:
CN- cyanide
HCO3- hydrogen carbonate (bicarbonate)
NH4+ ammonium
Polyatomic Ions
You will need to memorize the following:
Ammonium
Acetate
Hydroxide
Nitrite
Nitrate
Bicarbonate
Carbonate
Chromate
Sulfate
Phosphate
NH4+1
C2H3O2-1
OH-1
NO2-1
NO3-1
HCO3-1
CO3-2
CrO4-2
SO4-2
PO4-3
Oxyanions
Polyatomic ions that contain oxygen
Name depends on number of oxygen
atoms
Oxyanions (cont.)
If two oxyanionsMost oxygens: -ate
Least oxygens: -ite
Example
NO3- : nitrate
NO2- : nitrite
Oxyanions (cont.)
If more than two oxyanions
Most oxygens: “Per- …. –ate”
“-ate”
“-ite”
Least oxygens: “Hypo- …. –ite”
Example
ClO4- : perchlorate
ClO3- : chlorate
ClO2- : chlorite
ClO- : hypochlorite
Polyatomic Ion Quiz
Sodium hypochlorite
Potassium sulfate
Magnesium peroxide
Ammonium chloride
Lithium nitrate
Potassium phosphate
NaClO
K2SO4
MgO2
NH4Cl
LiNO3
K3PO4
Polyatomic Ion Quiz
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Bicarbonate
Acetate
Bisulfite
Permanganate
Nitrite
Cyanide
Hydroxide
Bisulfate
Nitrate
What’s your favorite polyatomic ion?
Binary Molecular Compounds
Composed of molecules (covalently
bonded!)
A nonmetal bonded to another nonmetal
Examples:
SO3
ICl3
CH4
H2O
Prefixes for Naming Binary
Molecular Compounds
1
2
3
4
5
6
7
8
9
10
monoditritetrapentahexaheptaoctanonadeca
Naming Binary Molecular
Compounds
Which element goes first?
Second element
Smaller group number
If same group- greater period number
Use prefix only if there is more than one atom
Prefix indicating number of atoms + root of the name
of the element + -ide
General order of elements in binary compounds:
C, P, N, H, S, I, Br, Cl, O, F
Naming Binary Molecular
Compounds
Examples:
SO3 – sulfur trioxide
BrCl3 – bromine trichloride
PBr5 – phosphorus pentabromide
N2O5 – dinitrogen pentoxide
Naming Binary Molecular
Compounds
N2O
CCl4
NO
CO2
N2O3
P4O10
Dinitrogen monoxide
Carbon tetrachloride
Nitrogen monoxide
Carbon dioxide
Dinitrogen trioxide
Tetraphosphorus decoxide
Naming Binary Molecular
Compounds- More Practice!
Disulfur dioxide
Silicon tetrafluoride
Sulfur monoxide
Phosphorus trioxide
Boron trifluoride
Diphosphorus pentoxide
S2O2
SiF4
SO
PO3
BF3
P2O5
Acids
Acid- a type of molecular compound
Two types
Binary acids- made up of two elements- hydrogen, and one
of the halogens (F, Cl, Br, I)
Oxyacids- contain hydrogen, oxygen, and a third element
Examples
Binary acids:
HCl- hydrochloric acid; HF- hydrofluoric acid
Oxyacids:
H2SO4: sulfuric acid
HNO3: nitric acid
Formula Mass
The sum of the atomic masses of all
atoms represented in its formula
Units = amu (atomic mass units)
Example: What is the formula mass of
water?
2 H atoms @ 1.01 amu each = 2.02 amu
1 O atom @ 16.00 amu each = 16.00 amu
Total mass of water = 16.00 + 2.02 = 18.02
Formula Mass
Find the formula mass of the following:
KClO3
H2SO4
Mg(NO3)2
C12H22O11
Molar Mass
The mass in grams of one mole of a
substance
If we have 1 mole of H2O, we have
2 moles of H atoms
1 mole of O atoms
Molar Mass (cont.)
How many moles of each atom are in the
following?
CaCl2
NaOH
KMnO4
NH4OH
Mg(NO3)2
Molar Mass (cont.)
Once we know the number of moles of
each atom, we can calculate the molar
mass.
In H2O:
2 moles H
x 1.01 g H = 2.02 g H
1 mole H
1 mole O
x 16.00 g O = 16.00 g O
1 mole O
Molar Mass (cont.)
Total mass of 1 mole H2O
2.02 g + 16.00 g = 18.02 g/mol
Molar Mass (cont.)
Determine the molar mass of the following:
CaCl2
NaOH
KMnO4
NH4OH
Mg(NO3)2
Molar Mass as a Conversion Factor
Can use molar mass as a conversion
factor to determine number of moles
How many moles of H2O are in 34.32 g?
Molar Mass as a Conversion Factor
How many molecules of NaCl can be
found in a sample containing 45.43 g?
Molar Mass as a Conversion Factor
How many carbon atoms are in a 23.43 g
sample of CO2?
Fun With Conversions!
Ibuprofen, C13H18O2, is the active
ingredient in Advil.
Find its molar mass
If the tablets in the bottle contain a total of 33
g of ibuprofen, how many moles of ibuprofen
are in the bottle?
How many molecules of ibuprofen are in the
bottle?
What is the total mass in grams of carbon in
33 g of ibuprofen?