FTCE Chemistry SAEPreparation Course

Session 3

Lisa BaigInstructor

Course OutlineSession 1

Review Pre TestCompetencies 1 & 2

Session 2Competency 5

Session 3Competency 3

Session 4Competency 4

Session 5Competencies 6, 7 and 8

Post Test

Session Norms

• Respect– No side bars– Work on assigned materials only– Keep phones on vibrate– If a call must be taken, please leave the

room to do so

Homework Review

Any questions from last night?

Chemistry Competencies

1. Knowledge of the nature of matter (11%)2. Knowledge of energy and its interaction with

matter (14%)

3. Knowledge of bonding and molecular structure (20%)

4. Knowledge of chemical reactions and stoichiometry (24%)

5. Knowledge of atomic theory and structure (9%)6. Knowledge of the nature of science (13%)7. Knowledge of measurement (5%)8. Knowledge of appropriate laboratory use and

procedure (4%)

Electronegativity

• Fluorine is the most electronegative element.

• Pattern of increasing electronegativity moves from bottom to top, and from left to right across the periodic table.

Chemical BondMutual electrical attraction between the

nuclei and valence electrons of different atoms that bind the atoms together

Atoms would like to have 8 Valence electrons. These bonds help the atoms to achieve

their full valence shells

Three TypesIonic

CovalentMetallic

Ionic Bond• Force of attraction between oppositely

charged ions• Occurs between Metal and Non-Metal

elements• The Non-metal “steals” the valence

electron(s) from the Metal• Forms a crystalline structure of these

positive and negative charges• Typically solids at room temperature

Ionic Character

• Ionic Bonds are bonds with > 50% ionic character

• Difference in Electronegativity of involved atoms is >1.7

Covalent Bond• Sharing of valence electron pairs by 2 atoms• Occurs between 2 Non-metal elements

– Or the SAME non-metal element

• Can share one, two or three pairs of electrons– Single Bond = 1 pair (1 sigma)– Double Bond = 2 pairs (1 sigma, 1 pi)– Triple Bond = 3 pairs (1 sigma, 2 pi)

• Sharing can also be “unequal”– Called a POLAR covalent bond

• Typically liquids or gases at room temperature

Character• Ionic Character:

– Polar Covalent Bonds have between 5% and 50% ionic Character

– Non-Polar Covalent Bonds have less than 5% ionic character

• Difference in Electronegativities– Polar Covalent Bonds have between 0.3

and 1.7 as a difference in electronegativities

– Non-Polar Covalent bonds have less than 0.3 difference in electronegativities

Break Time

Take a 10 minute

break

Ionic Compounds

• Ion names are used in combination• Cation- same as the element

– Transitional Metals use Roman Numerals to represent Charge

• Anion- replace the ending syllable of the element name with –ide

• Polyatomic Ions- use the name of that ion- do not try to rename.

Use “criss-cross” to determine charges

CuCl2

Copper (II) ChlorideCuO

Copper (II) OxideNaCl

Sodium ChlorideKI

Potassium IodideMg3N2

Magnesium NitridePbO2

Lead (IV) Oxide

Lewis Structures

• A way to show the octet rule in molecules

Practice

• Draw the lewis structures for– Ammonia (NH3)

– Water (H2O)

– Phosphorus Trifluoride (PF3)– Hydrogen Cyanide (HCN)– Ozone (O3)

– Formaldehyde (CH2O)

VSEPR

•AB5

•Trigonal bipyramidal

•AB6

•Octahedral

VSEPR• AB4

– Tetrahedral– 109.50 Bond Angles

• AB3– Trigonal Planar– 1200 Bond Angles

• AB2– Linear– 1800 Bond Angles

VSEPR• AB2E

– Bent or Angular

• AB2E2

– Bent or Angular

• AB3E– Trigonal Pyramidal

Polarity?

• The potential for opposite charges at different areas of a molecule

Shape and Polarity?

• What is the shape and polarity of the following molecules?– Water– Ammonia– Carbon Tetrachloride– Carbon Dioxide– Hydrogen Chloride

Hybrids

• Atoms “don’t like” to have empty orbitals• Hybridization

– Mixing of 2 or more atomic orbitals of similar energies to produce new hybrid orbitals of equal energies

• It works like this– Methane: CH4 Normally: 1s22s22p2

– Through hybridization- it forms an “sp” orbital, with 4 electrons total

– New arrangement: 1s22(sp3) 4

Hybrid OrbitalsAtomic Orbitals

Type of Hybrid

Number of

Orbitals

MolecularGeomet

rys p sp 2 1800

Linear

s p p sp2 3 1200

Trigonal Planar

s p p p sp3 4 109.50

Tetrahedral

What type of hybrid?

• Beryllium fluoride– BeF2

– sp• Ammonia

– NH3

– sp2

• Methane– CH4

– sp3

Break Time

Take a 10 minute

break

Spectroscopy

• Devices that measure the interaction between matter and energy

• Absorption– Measures the wavelengths of

electromagnetic waves absorbed by a substance

• X-Ray spectroscopy – Used to determine elemental

composition and types of bonding

Spectroscopy

• UV– Used to quantify DNA and Protein

concentration• Infrared

– Used to determine bond type• Bonds resonate when exposed to the

radiation

• Nuclear Magnetic Imaging (NMR)– Used to determine bond structure

Simple Organics

• Alkanes (end in –ane)– Containing only single bonds– CnH2n+2

• Alkenes (end in –ene)– Containing at least one double bond– CnH2n

• Alkynes (end in –yne)– Containing at lease one triple bond– CnH2n-2

Simple OrganicsName Number of Carbons

Meth- 1

Eth- 2

Prop- 3

But- 4

Pent- 5

Hex- 6

Hept- 7

Oct- 8

Non- 9

Dec- 10

Functional GroupsCompound

Type Image Suffix or Prefix

Alcohol - -OH -ol

Haloalkane -X Halo-

Amine -CN- -amine

Aldehyde -COH -al

Ketone -COC- -one

Carboxylic Acid -COOH -oic acid

Ester -COOC- -oate

Amide -CON- -amide

Naming and Formulas

• Numbers are used in the name to designate locations of the following– Types of bonds– Branches– Attached functional groups

• For Example– 2,2,4- trimethylpentane– 1-pentyne– 2,3,4- trimethylnonane– 2-methyl 3-hexene– 2- propanol

Macromolecules

• Carbohydrates– Chains of carbon, hydrogen and oxygen.– Isomers

• Lipids– Fatty acids- Chains of Carbon and Hydrogen

• Proteins– Chains of Amino acids– Differ in their R group

• Nucleic Acids– Chains of Nucleic Acids

Organic Compound Naming• Numbers are used in the name to

designate locations of the following– Types of bonds– Branches– Attached functional groups

• For Example– 2,2,4- trimethylpentane– 1-pentyne– 2,3,4- trimethylnonane– 2-methyl 3-hexene– 2- propanol

Homework

• Diagnostic Exam in your AP Chem Prep book- Page 17-26

• Only answer the questions for these Chapters & Questions– Chapter 5 #1,3– Chapter 11 #41-43, 46– Chapter 18, #86

Bibliography

• VSEPR Theory GIF’s– Rindge, R. (Artist). (1998). Shapes of molecules.

[Web]. Retrieved from http://chemmybear.com/shapes.html