To make a chemical bond, atomsTo make a chemical bond, atomsWill overlap their outer orbitalsWill overlap their outer orbitals
The point at which the potential energy is a minimum is called the equilibrium bond distance
The degree of overlap is determined by the system’s potential energy
equilibrium bond distance
2s
These new orbitals are called hybrid orbitals
The process is called hybridization
What this means is that both the s and one p orbital are involved in bonding to the connecting
atoms
Formation of sp hybrid orbitalsFormation of sp hybrid orbitals
The combination of an s orbital and a p orbital produces 2 new orbitals called sp orbitals.
Formation of spFormation of sp22 hybrid orbitalshybrid orbitals
Formation of spFormation of sp33 hybrid orbitalshybrid orbitals
Hybrid orbitals can be used to explain Hybrid orbitals can be used to explain bonding and molecular geometrybonding and molecular geometry
Based on Lewis structures we can know the shape or “geometry” of molecules
VSEPR stands for Valence Shell Electron Pair Repulsion
VSEPR, as the name suggests, predicts geometry based on the repulsion of electron pairs (in bonds or by themselves)
Electrons around the central nucleus repel each other. Thus, resulting structures have atoms maximally spread out.
Each shape containing 2-6 peripheral atoms has a name
Sometimes the molecules are represented by ABY, where Y is the # of peripheral atoms
▪ AB2 = linear▪ AB3 = planar triangular▪ AB4 = tetrahedral (tetra = 4 faces)▪ AB5 = trigonal bipyramidal (2 pyramids)▪ AB6 = octahedral (octa = 8 faces)▪ Online chart
Rules for Predicting Molecular Rules for Predicting Molecular GeometryGeometry
1. Sketch the Lewis structure of the molecule or 1. Sketch the Lewis structure of the molecule or ionion
2. Count the electron pairs and arrange them in 2. Count the electron pairs and arrange them in the way that minimizes electron-pair repulsion.the way that minimizes electron-pair repulsion.
3. Determine the position of the atoms from the 3. Determine the position of the atoms from the way the electron pairs are shared.way the electron pairs are shared.
4. Determine the name of the molecular structure 4. Determine the name of the molecular structure from the position of the atoms.from the position of the atoms.
5. Double or triple bonds are counted as one 5. Double or triple bonds are counted as one bonding pair when predicting geometry.bonding pair when predicting geometry.
Ammonium – NH4+ Nitrite – NO2
-
Nitrate – NO3- Hydroxide – OH-
Hypochlorite – ClO- Chlorite – ClO2-
Chlorate – ClO3- Perchlorate – ClO4
-
Carbonate – CO32- Sulfite – SO3
2-
Sulfate – SO42- Peroxide – O2
2-
Phosphate – PO43-
For more lessons, visit www.chalkbored.com
Polyatomic ions that you have to memorize (pg 226 of Modern Chem)
NH4+ It’s AB4 = tetrahedral
NO3- It’s AB3E
= Trigonal Pyrimidal
NO2- It’s AB2E2
= Angular/bent
1. Cation first, then anion
2. Monatomic cation = name of the element
Ca2+ = calcium ion
3. Monatomic anion = root + -ide
Cl = chloride CaCl2 = calcium chloride
Binary Ionic Compounds:Binary Ionic Compounds:
Examples:
NaCl
ZnI2
Al2O3
sodium chloride
zinc iodide
aluminum oxide
Complete the names of the following binary compounds:Na3N sodium ________________
KBr potassium ________________
Al2O3 aluminum
________________
MgS _________________________
Elements that can have more than one
possible charge MUST have a Roman
Numeral to indicate the charge on the
individual ion.
1+ or 2+ 2+ or 3+Cu+, Cu2+ Fe2+, Fe3+
copper(I) ion iron(II) ion copper (II) ion iron(III) ion
These elements REQUIRE Roman Numerals because they can have more than one possible charge:anything except Group 1A, 2A, Ag, Zn, Cd, and Al
(You should already know the charges on these!)Or another way to say it is: Transition metals and the metals in
groups 4A and 5A (except Ag, Zn, Cd, and Al) require a Roman Numeral.
FeCl3 (Fe3+) iron (III) chlorideCuCl (Cu+ ) copper (I) chlorideSnF4 (Sn4+) tin (IV) fluoridePbCl2 (Pb2+) lead (II) chloride
Fe2S3 (Fe3+) iron (III) sulfide
Complete the names of the following binary compounds with variable metal ions:
FeBr2 iron (_____) bromide
CuCl copper (_____) chloride
SnO2 ___(_____ ) ______________
Fe2O3 ________________________
Hg2S ________________________
Writing FormulasWrite each ion, cation first. Don’t
show charges in the final formula.Overall charge must equal zero.
If charges cancel, just write symbols. If not, use subscripts to balance charges.
Use parentheses to show more than one of a particular polyatomic ion.
Use Roman numerals indicate the ion’s charge when needed (stock system)
Sodium SulfateNa+ and SO4 -2
Na2SO4
Iron (III) hydroxideFe+3 and OH-
Fe(OH)3
Ammonium carbonateNH4
+ and CO3 –2
(NH4)2CO3
Contains at least 3 elementsThere MUST be at least one polyatomic ion
(it helps to circle the ions)*Most polyatomic ions are negatively
charged and most are oxyanions – containing oxygen*
Examples:NaNO3 Sodium nitrateK2SO4 Potassium sulfateAl(HCO3)3 Aluminum bicarbonate
or Aluminum hydrogen carbonate
Match each set with the correct name:1. Na2CO3 a) magnesium sulfite
MgSO3 b) magnesium sulfateMgSO4 c) sodium carbonate
2 . Ca(HCO3)2 a) calcium carbonate
CaCO3 b) calcium phosphate Ca3(PO4)2 c) calcium bicarbonate
Name the following:
1. Na2O2. CaCO3
3. PbS2
4. Sn3N2
5. Cu3PO4
6. HgF2
Write the formula:1. Copper (II) chlorate2. Calcium nitride3. Aluminum
carbonate4. Potassium bromide5. Barium fluoride6. Cesium hydroxide
CH4 methaneBCl3 boron trichloride
CO2 Carbon dioxide
All are formed from two or more nonmetals.
Ionic compounds generally involve a metal and nonmetal (NaCl)
Prefix System (binary compounds)
1. Less electronegative atom comes first.
2. Add prefixes to indicate # of atoms. Omit mono- prefix on the FIRST element. Mono- is OPTIONAL on the SECOND element (in this class, it’s NOT optional!).
3. Change the ending of the second element to -ide.
PREFIXmono-di-tri-tetra-penta-hexa-hepta-octa-nona-deca-
NUMBER123456789
10
• CCl4
• N2O
• SF6
• carbon tetrachloride
• dinitrogen monoxide
• sulfur hexafluoride
• arsenic trichloride
• dinitrogen pentoxide
• tetraphosphorus decoxide
• AsCl3
• N2O5
• P4O10
Fill in the blanks to complete the following names of covalent compounds.
CO carbon ______oxide
CO2 carbon _______________
PCl3 phosphorus
_______chloride
CCl4 carbon ________chloride
N2O _____nitrogen _____oxide
1. Dinitrogen monoxide2. Potassium sulfide3. Copper (II) nitrate4. Dichlorine heptoxide5. Chromium (III) sulfate6. Iron (III) sulfite7. Calcium oxide8. Barium carbonate9. Iodine monochloride
1.1. BaIBaI22
2.2. PP44SS33
3.3. Ca(OH)Ca(OH)22
4.4. FeCOFeCO33
5.5. NaNa22CrCr22OO77
6.6. II22OO55
7.7. Cu(ClOCu(ClO44))22
8.8. CSCS22
9.9. BB22ClCl44
AcidsAcids Compounds that form HCompounds that form H++ in water. in water.
Formulas usually begin with ‘H’.Formulas usually begin with ‘H’.
In order to be an acid instead of a gas, In order to be an acid instead of a gas,
binary acids must be aqueous (dissolved in binary acids must be aqueous (dissolved in
water)water)
Ternary acids are ALL aqueousTernary acids are ALL aqueous Examples:Examples:
HCl HCl (aq)(aq) – hydrochloric acid – hydrochloric acid
HNOHNO33 – nitric acid – nitric acid
HH22SOSO44 – sulfuric acid – sulfuric acid
Anion Ending Acid Name
-ide hydro-(stem)-ic acid
-ate (stem)-ic acid
-ite (stem)-ous acid
No No OxygenOxygen
with with Oxygen Oxygen
An easy way to remember which goes with which…An easy way to remember which goes with which…
““In the cafeteria, you In the cafeteria, you ATEATE something something ICICky”ky”
h yd ro - p re fix-ic e n d ing
2 e le m e n ts
-a te e nd ingb e com es-ic e nd ing
-ite e nd ingb e com es
-o us e nd ing
n o h yd ro- p re fix
3 e le m e n ts
AC ID Ss ta rt w ith 'H '
• HBr HBr (aq)(aq)
• HH22COCO33
• HH22SOSO33
• No oxygen, No oxygen, --ideide
• Has oxygen, Has oxygen, -ate-ate
• Has oxygen, Has oxygen, -ite-ite
hydrohydrobromic bromic
acidacid
carboncarbonicic
acidacid
sulfursulfurousous
acidacid
• hydrofluoric acidhydrofluoric acid
• sulfuric acidsulfuric acid
• nitrous acidnitrous acid
• 2 elements2 elements
• 3 elements, 3 elements, -ic-ic
• 3 elements, 3 elements, -ous-ous
HF HF (aq)(aq)
HH22SOSO44
HNOHNO22
HH++ F- F-
HH++ SO SO442-2-
HH++ NO NO22--
HI HI (aq)(aq)
HClHCl HH22SOSO33
HNOHNO33
HIOHIO44
Nomenclature Summary Flowchart