Class 1

Question 1

What is a DOU?

Answer 1

Degree of unsaturation

Question 2

How do you measure a DOU?

Answer 2

One double, triple or ring is = to one pi bond

Question 3

How do we treat Halogens, N and O in counting DOU?

Answer 3

Halogen treat as an extra H
N subtract the number of N from the number of Hs
O ignore

Question 4

Whats the relationship between energy and stability?

Answer 4

Increase in energy decreases stability

Question 5

What are the characteristics of a molecule that is unstable?

Answer 5

Increased energy
Reactive
Decrease lifetime

Question 6

What are the characteristics of a molecule that is stable?

Answer 6

Decreased energy
Less reactive
Increase lifetime

Question 7

What is ring strain?

Answer 7

Destabilization of of ring weakens the C–C bonds and increases reactivity

Question 8

What are examples of e- withdrawing and donating?

Answer 8

Withdrawing: O and Halogens

Donating: Alkyl groups

Question 9

What is the order of electronegativity?.

Answer 9

F O N Cl Br I S C H

Question 10

What is the order of strongest Carbocations?

Answer 10

(Most stable) 3>2>1>Mehtyl (least stable)

Question 11

What is the order of strongest Carbanions?

Answer 11

(Most reactive) 3>2>1>Methyl (least reactive)

Question 12

What are the 3 things that resonance contributors have

Answer 12

1. Octet rule
2. Least formal charge
3. • charge on more electronegative element

Question 13

What is the relationship between acids and bases?

Answer 13

Stronger the acid the weaker the conjugate base

More stable the conjugate base the stronger the acid

Question 14

What are the factors influencing acidity by alternating conjugate stability?

Answer 14

1. Electronegativity: more electronegative holds charge better
2. Resonance: increases stability of anionic conjugate base
3. Induction: Depends on proximity to electronegativity

Question 15

What us a Nu-?

Answer 15

Nucleus loving
Have a full or partial - charge
Donates e- (Lewis base)

Question 16

What are some good Nu-?

Answer 16

OH-, Br-, Cl-, OR-, H2O, NH2-, NH3

Question 17

What effect does size, electronegativity and charge have on Nu-?

Answer 17

Increase size increases Nu- strength
Decrease electronegativity increases Nu- strength
- charge increase Nu- strength

Question 18

What are E+?

Answer 18

e- loving
Accepts e- pair (Lewis acid)
Has full or partial + charge

Question 19

What makes a good leaving group?

Answer 19

Resonance stabilized LG
Weak Base (Cl

Question 20

What makes a bad leaving group?

Answer 20

Strong bases (OH-, RO-,NH2-)
Acid Catalysts (Protonation)

Question 21

What are ugly leaving groups?

Answer 21

H- or C- are almost never LGs

Question 22

What does RICE stand for for making molecules more stable?

Answer 22

Resonance
Induction
Size
Electronegativity

Question 23

What are isomers?

Answer 23

Different compound with the same molecular formula

Question 24

What are structural (constitutional) isomer?

Answer 24

Different atomic connectivity

Different chemical and physical properties

Question 25

What are conformational isomers?

Answer 25

Different by rotation around the the sigma bond Same chemical and physical properties Same atomic connectivity

Question 26

What are the 3 position in conformational isomers and their stabilities?

Answer 26

Anti: Most stable Gauche: Intermediate Syn: Eclipsed, most unstable

Question 27

What is chirality?

Answer 27

Non-superimposable on mirror image | No plane of symmetry

Question 28

What are the characteristics of a chiral centre?

Answer 28

sp3 tetrahedral 4 Different groups

Question 29

What are the 2 forms of optical activity?

Answer 29

d+: clockwise d-: counterclockwise

Question 30

What are Stereoisomers?

Answer 30

Different spatial arrangement

Question 31

What are enantiomers?

Answer 31

Non-superimposable Opposite configuration at all chiral centres Same physical and chemical properties

Question 32

What is a racemic mixture?

Answer 32

1:1 R and S | optically inactive

Question 33

What are diasteriomers?

Answer 33

Non-superimposable At least 1 chiral centre is the same (need 2 or more) Different physical and chemical properties

Question 34

What are geometric isomers?

Answer 34

Double bond or ring structures Different chemical and physical properties No chiral center (Z and E)

Question 35

What is an epimer?

Answer 35

Diasteriomer that differs in only 1 chiral centre

Question 36

What is a mess compound?

Answer 36

Plane of symmetry and even the number of chiral centres must have opposite configurations Not optically active