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CONCEPT: HYBRID ORBITAL THEORY The Aufbau Principle states that electrons fill orbitals in order of increasing energy. If carbon has only two unfilled orbitals, why does it like to make 4 bonds? EXAMPLE: Carbon sp 3 Hybridization Many atoms prefer to blend some of their 2 nd shell orbitals together to make new orbitals Page 2
CONCEPT: HYBRIDIZATION SUMMARY Hybridization can be predicted by the determine the number of on an atom Where a bond site is equal to any or EXAMPLE: Predict the hybridization of the following reactive intermediates Page 3
CONCEPT: MOLECULAR GEOMETRY Molecular geometry is based on VSEPR theory: Bond sites will each other as much as possible. The molecular geometry predicts what shape the hybridized atom will have. EXAMPLE: Predict the hybridization and molecular geometry of the following selected atoms: Page 4
PRACTICE: Determine the hybridization and molecular geometry of the following selected atoms: a. b. Page 5
CONCEPT: ELECTRONEGATIVITY Chemical bonds are formed when the sharing of valance electrons between two or more atoms takes place. The of sharing will determine the identity and strength of the chemical bond. An unequal sharing of electrons in one direction along a bond is called a ( ) The charge between any two bonded atoms is related to their difference in electronegativity Generalizations: Bonds to carbon and hydrogen are always Bonds between two identical atoms are always Adjacent atoms on the periodic table are Lone pairs are exist when atoms have asymmetrical dipoles Page 6
PRACTICE: Which of the following molecules contain dipoles? Which contain net dipoles? PRACTICE: Which of the solvents below is apolar? Which is polar? Page 7
CONCEPT: INTERMOLECULAR FORCES IMF s are what make molecules. Without them everything would be Boiling point / melting point questions are always directly referring to the strength of between molecules. 1. Hydrogen Bonding (H) Bound to small, highly electronegative atoms: 2. Dipole-dipole (net dipole force) 3. Van der Waals (London Dispersion Forces) Increase with: a. Size b. Ring > Chain > Branched Page 8
PRACTICE: Which of the following pairs of molecules would have the highest boiling point? 1. OR 2. OR 3. OR 4. OR Page 9
CONCEPT: SOLUBILITY Only one rule: dissolves EXAMPLE: PRACTICE: Circle the following molecules would you expect to be miscible in an aqueous solution? a. b. c. d. e. f. Page 10
CONCEPT: FUNCTIONAL GROUPS We can group several millions of different molecules into subsets of similar 1. Hydrocarbons All carbon groups regardless of size can be symbolized using an group. When an alkane is attached to a greater carbon chain, it is given an suffix. (i.e. group) Carbons are given a degree based on how many other they are attached to Hydrogens possess the degree as the carbon they are attached to Degrees are expressed as primary, secondary, tertiary and quaternary (1⁰, 2⁰, 3⁰, 4⁰) EXAMPLE: Determine the degree of the indicated carbons and hydrogens Page 11
2. Alkyl Halide Any R group directly attached to a halogen. The degree of alkyl halide is determined the same way as The carbonyl is NOT a functional group, but it is a major component of many functional groups 3. Alcohol 6. Carboxylic Acid ( ) Degree of alcohol is determined the same The acid of organic chemistry way as 4. Amine 7. Amide ( ) Degree of alcohol is determined the same Degree of alcohol is determined the same way as. way as. 5. Ether 8. Ester ( ) Page 12
9. Carbonyls The term carbonyl is not the proper name of the functional groups because the functionality of the group depends on its location on the carbon chain.. Ketone ( ) Aldehyde ( ) - carbonyl group - carbonyl group 10. Nitrile 11. Benzene Directly attached to R group ( )( ) Extra CH2 between R group ( )( ) EXAMPLE: Identify all the functional groups in the following compound. Show degrees where applicable. Page 13
12. Other Carbonyl Compounds Acyl Chloride ( ) Anhydride ( ) 13. Sulfur Compounds Page 14
PRACTICE: Identify all the functional groups in the following compound. Show degrees where applicable. a. b. c. Page 15