Chem 163 Mid term

Steric Number: The number of attached atoms and the number of lone pairs

Carbon is ususally bonded to 4 things with four single bonds (sigma bonds) but you can also have pi bonds

Alkyl groups : Sec-butyl is R — CH(—CH3)—CH3

Tert-butyl: R—C(—CH3)2—CH3

Acetylene : C2H2

Acetone: CH3C(O)CH3

Vinyl Group: CH2=CH-

Styrene: C6H5CH=CH2

Sigma bonds are formed by : Head -to Head overlap of orbitals these are always single bonds.

Pi bonds are formed though : side to side overlap or orbitals these are in double bonds

Week 6

A chiral carbon has : 4 unique sub stituents

Structural isomer : same formula differnt arrangements of attoms ( Chain (branched or straight) Positon (1-ene 2- ene) Functional (cyclo alkane))

Stereoisomers: Same formula AND same position but different 3d arrangement (Cis/Trans - optical)

Arene: Cyclic unsaturated compounds (benzene) aromatic hydrocarbons, conjugated, the electron density is delocalized the double bonds really move

Geometry of an arene: planar

Hybridization of carbons on an Arene: sp2

Huckels rule : Predicts a planar ring molecule will have aromantic properites if it has 4n+2pi e- when n is a non negative intereger

In Huckels rule when N is not an integer : the compound is Antiaromatic and unstable.

- Alkyl : -CH3

- Alkenyl : -CH=CH2

-Alkynyl : -C=-CH

-Phenyl : C6H5

-amino/ amine : -N(H,R)2

-hydroxyl/ alcohol: -OH

-alkoxy/ether: R-O-R’

- Alkyl Halide : R-F,Br, CL, I

- thiol : -SH

- Aldehyde: -C(=O)-H

-Ketone/-one: R-C(=O)-R

-Ester/- ate : -C(=O)-O-R

-Carboxylic acid / ic Acid: -C(=O)-OH

Amide : -C(=O)-N(H,R)2

OIL : Oxidation is Loss

RIG : Reduction is gain

Oxidation is : the lost of electrons and H and adding oxygen

Reduction : is Gaining electrons and H and losing oxygen

A first degree alcohol: is connected to 1 other carbon

a second degree alcohol: is connected to 2 other carbons

a third degree alcohol: is connected to 3 other carbons

Alcohols can be oxidized to give: Aldehydes and ketones

A primary alcohol can be oxidized to : aldehyde

A Secondary Alcohol can be oxidized to : a Ketone

Aldehyde can be further oxidized to a : carboxylic acid

Replacing the H on an alcohol with a r group gives a : Ether

Replacing the H on a carboxylic acid with an R group gives a: Ester

Ammonia : NH3

Primary Amine : R-NH2

Secondary Amine: R-N(H)-R

Tertiary Amine : N(R)3

Carboxylic acid + a secondary amine yields: Amide + water

Constructive interference : Bonding interaction (No star) no node

Destructive interference : Antibonding interaction (with star) Node

Orthogonal : when p and s orbitals are perpendicular

If one s and p orbital is head to head, and the the other 2 are orthogonal those 2 are : nonbonding

Linear Combination of Atomic Orbitals

LCAO The number of Molecular orblitals is equal to : Ther number of atomic orblitals brought by the atoms that are being combined

LCAO molecular Bonding Molecular orbitals are lower in energy than the : Parent orbitals

LCAO Antibonding orbitals are higher in energy that the : Parent orbitals

LCAO Electrons in the Atomic orbitals are assigned to____ filling from : Molecular orbitals , lowest to higher energy

To form molecular orbital there are 3 requirements : 1) AOs are close to each other 2) AO,s have similar energy 3 AO’s have same symmetry

Sigma orbitals do not change : Conformation along the axis of bonding

Pi molecular orbitals are ___ to rotation: Antisymmetric

Gerade : symmetric to inversion

Ungerade : asymmetric to inversion

Most electronegative atom has ___ atomic energy : Lower

In Heteronuclear Diatomic molecules, electrons that don’t interact with bonding are at the : same energy level

For bonds not involved in resonance the bond order is equal to : the bonds

For bonds involved in resonance you have : fractional bond orders

For bonds involved with resonance take the ___ of the two bond orders: Average

Bond order is equal to ____ minus ____ over___: bonding electrons, antibonding electrons, 2

In Heteronuclear Diatomic molecules, the electronegative species contributes more to the _____ and the less electron negative species contributes more to the ____: Bonding orbitals, Antibonding orbitals

Pz orbitals can have _____ bonding, Px and Py can _____ bond: Sigma, Pi

Sigma bonds are _____ in comparison to pi bonds because there is more _____: Stronger overlap

LUMO stands for: Lowest Unoccupied Molecular Orbital

HOMO stands for : Highest Occupied Molecular Orbital

1,3 butadiene has four p orbitals from lowest to highest energy the conformations are : All bonding, two bonding pairs, one bonding pair, all antibonding

Deprotonation of a carboxylic acid with a _____ will produce a _____: Base, Carboxylate ion [R(=O)-O-]

Carboylate ions have _____, therefore instead of one ____ and one ___ charge, they bothe have ____ charge: resonance, negative, positive, -1/2

Amides can ___ their charge for stability: Delocalize

Alkene + HX yields : Alkyl Halide (Markovnikcov)

Alkene + water (with ___catalyst) yields : Acid, alcohol (Markovnikcov)

Alkene + alcohol (with ___ catalyst) yields : ether (Markovnikov)

Alkene + halogen yields ____ and give ___ product: Dihaloalkane, Trans

Carboxylic acid + alcohol (with ___ catalyst) yields: acid, ester + water

Carboxylic acid + Amine yields: amide + water

Carboxylic acid + -B; yields: Carboxylate + HB+

Alkyl halide + OH- yields alcohol + x-

Markovnikov’s rule states : The halogen/ hydroxyl/ alkoxy group will end up on the carbon with the fewest hydrogens

Halogenation is stereoselective meaning : the two halogen atoms will form bonds on opposites sides of the pi bond

Fischer Esterification : adding two groups containing oxygen to make an ester

The acidic hydrogen of carboxylic acids can be removed using : Bronsted lowery bases/ proton acceptors

In alkene hydrogenation, the hydrogens add syn meaning : they add on the same face of the carbon

Nuleophile is : an electron pair donor