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