Organic Chemistry Ch 3. Bonding

Question 1

Quantum numbers

Answer 1

Describe the size, shape, orientation, and number of atomic orbitals an element possesses

Question 2

Atomic orbitals

Answer 2

-

Question 3

Principal quantum number

Answer 3

n - describes the energy level (shell) in which an electron resides and indicates the distance from the nucleus to the electron, possible values range from 1 to infinity

Question 4

Azimuthal quantum number

Answer 4

l - determines the substsell in which an electron resides, values range from 0 to n-1,, subshell also often indicated with a letter l=0=s, l=1=p, l=2=d, l=3=f

Question 5

Magnetic quantum number

Answer 5

ml - determines the orbital in which an electron resides, possible values range from -l to l, different orbitals have different shapes, s are spherical, p are dumbbell shaped and located on x,y, or z axis

Question 6

Spin quantum number

Answer 6

ms - describes the spin of an electron, possible values are +/- 1/2

Question 7

Bonding orbitals

Answer 7

Created by head to head or tail to tail overlap of atomic orbitals of the same sign and are energetically favorable

Question 8

Antibonding orbitals

Answer 8

Created by head to head or tail to tail overlap of atoms orbitals that have opposite signs and are energetically unfavorable

Question 9

Single bonds

Answer 9

Sigma bonds that contain 2 electrons

Question 10

Sigma bonds

Answer 10

Contain 2 electrons

Question 11

Double bonds

Answer 11

Contain one sigma bond and one pi bond

Question 12

Pi bonds

Answer 12

Created by the sharing of electrons between two unhybridized p-orbitals that align side by side

Question 13

Triple bonds

Answer 13

Contain one sigma and two pi bonds

Question 14

Bond length

Answer 14

Multiple bonds are shorter and stronger than single bonds

Question 15

Bond flexibility

Answer 15

Multiple bonds are less flexible than single bonds because rotation is not permitted in the presence of a pi bond

Question 16

Bond strength

Answer 16

Multiple bonds are stronger than single bonds though sigma bonds are stronger than pi bonds

Question 17

sp3 hybridization

Answer 17

Has 25% s character and 75% p character, they form tetrahedral geometry with 109.5 degree bond angles, carbons with all single bonds are sp3 hybridized

Question 18

sp2 hybridization

Answer 18

Has 33% s character and 66% p character, they form trigonal planar geometry with 120 degree bond angles, carbons with one double bond are sp2 hybridized

Question 19

sp hybridization

Answer 19

Has 50% s character and 50% p character, they form linear geometry with 180 degree bond angles, carbons with two double bond or one triple bond are sp hybridized

Question 20

Resonance

Answer 20

Describes the delocalization of electrons in molecules that have conjugated bonds, increases the stability of a molecule, the various resonance forms all contribute to the true electron density of the molecule, the more stable the resonance form, the more it contributes, forms are favored if they lack formal charge, form full octets on electronegative atoms, or stabilize charts through induction and aromaticity

Question 21

Conjugation

Answer 21

Occurs when single or multiple bonds alternate, creating a system of unhybridized p-orbitals down the backbone of the molecule through which pi electrons can delocalize