ORGANIC 2: OCHEM 1 Review

Question 1

True or False

If a molecule can resonate, it is more basic.

Answer 1

False!

Resonance makes a molecule more stable and therefore more acidic.

Question 2

Define

Brønsted-Lowry Acid

Answer 2

Proton (H⁺) donor

Question 3

Define

Brønsted-Lowry Base

Answer 3

Proton (H⁺) acceptor

Question 4

What species will always be acids?

Answer 4

1. Strong acids (HCl, HBr, HI, H₂SO₄, H₃PO₄, etc.)
2. Uncommon Lewis acids (B.Al.Sn.Fe.Ti. + halogen)

Question 5

What species will always be bases?

Answer 5

1. Strong bases (NaOH, LiOH, etc.)
2. Any time an alkali or alkali earth metal is bound to a non-metal. (NaCH₃, LiCH₃, etc.)

Question 6

True or False

The stronger the base, the better a leaving group it will be.

Answer 6

False!

Weak bases are bad leaving groups.

Question 7

What are the three requirements for aromaticity?

Answer 7

1. The compound must be cyclic
2. The compound must be planar
3. The compound must have a Huckle number of pi electrons

Question 8

Answer 8

Question 9

Answer 9

Question 10

Answer 10

Question 11

Answer 11

Question 12

Answer 12

Question 13

Answer 13

Question 14

Answer 14

Question 15

Answer 15

Dissolving metal reduction (Na, NH₃, -78°C) cannot be used on terminal alkynes.

Question 16

Answer 16

Dissolving metal reduction (Na, NH₃, -78°C) cannot be used on terminal alkynes.

Question 17

Answer 17

Dissolving metal reduction (Na, NH₃, -78°C) cannot be used on terminal alkynes.

Question 18

Is the molecule shown below aromatic, anti-aromatic, or non-aromatic?

Answer 18

Aromatic

Question 19

Is the molecule shown below aromatic, anti-aromatic, or non-aromatic?

Answer 19

Non-aromatic

Cyclic rings 8 members and larger are not planar; fails requirement 2 so non-aromatic.

Question 20

Is the molecule shown below aromatic, anti-aromatic, or non-aromatic?

Answer 20

Anti-aromatic

Cyclic, planar, but does not contain a Huckle number of pi electrons

4n + 2 = 4

n = ½ (not a whole number, therefore not Huckle)

Question 21

Is the molecule shown below aromatic, anti-aromatic, or non-aromatic?

Answer 21

Aromatic

Carbanions are considered to be sp² hybridized.

Question 22

Is the molecule shown below aromatic, anti-aromatic, or non-aromatic?

Answer 22

Aromatic

Question 23

Is the molecule shown below aromatic, anti-aromatic, or non-aromatic?

Answer 23

Non-Aromatic

Cyclic, but not planar due to sp³ oxygens. If the oxygens gave up a lone pair to the pi cloud, there would not be a Huckle number of electrons.

4n + 2 = 8

n = 3/2

Since requirement #2 wasn’t met, the molecule is non-aromatic

Question 24

Is the molecule shown below aromatic, anti-aromatic, or non-aromatic?

Answer 24

Anti-Aromatic

Cyclic, planar, but does not contain a Huckle number of pi electrons

4n + 2 = 4

n = ½

Carbocations are sp² hybridized

Question 25

Is the molecule shown below aromatic, anti-aromatic, or non-aromatic?

Answer 25

Aromatic Group 3 elements only make 3 bonds, making them sp² hybridized with no lone pair

Question 26

Is the molecule shown below aromatic, anti-aromatic, or non-aromatic?

Answer 26

Aromatic

Question 27

Is the molecule shown below aromatic, anti-aromatic, or non-aromatic?

Answer 27

Anti-Aromatic Cyclic, planar, but non-Huckle number of electrons

Question 28

# Define Electron Donating Group (EDG)

Answer 28

An atom or group of atoms capable of donating electrons into a pi system. Generally defined as an electronegative atom containing a lone pair, or an alkyl group.

Question 29

# Define Electron Withdrawing Group (EWG)

Answer 29

An atom or group of atoms capable of withdrawing electrons from a pi system. Generally defined as an atom that is bound to an electronegative atom.

Question 30

# True or False Electron donating groups increase the acidity of a molecule.

Answer 30

False. EDG's increase the basicity of a molecule as it is providing more electron density, destabilizing the molecule.

Question 31

# True or False Electron withdrawing groups increase the acidity of a molecule.

Answer 31

True! EWG's increase the acidity of a molecule by spreading electron density out over more of the molecule.

Question 32

# Acidity Trends Hybridization

Answer 32

The more s-character an atom has, the more acidic it will be. (most acidic) sp \> sp² \> sp³ (least acidic)

Question 33

# Acidity Trends Electronegativity

Answer 33

If comparing two atoms in the same period, the more electronegative atom will be the more acidic atom.

Question 34

# Acidity Trends Size

Answer 34

If comparing two atoms in the same column, the larger atom will be the more acidic compound.

Question 35

# Acidity Trends Resonance

Answer 35

The compound that can resonate more will be more acidic.

Question 36

# Acidity Trends Inductive Electron Withdrawal

Answer 36

The closer an electronegative atom is to the most acidic proton, the more acidic the compound will be.

Question 37

What is the IUPAC priority list?

Answer 37

1. Alcohols 2. Amines 3. Alkenes \> Alkynes 4. Everything else

Question 38

What is the common name of the substituent shown below? What is the systematic name?

Answer 38

Common: isopropyl Systematic: (1-methylethyl)

Question 39

What is the common name of the substituent shown below? What is the systematic name?

Answer 39

Common: sec-butyl Systematic: (1-methylpropyl)

Question 40

What is the common name of the substituent shown below? What is the systematic name?

Answer 40

Common: tert-pentyl Systematic: (1,1-dimethylpropyl)

Question 41

What is the common name of the substituent shown below? What is the systematic name?

Answer 41

Common: tert-butyl Systematic: (1,1-dimethylethyl)

Question 42

When naming a molecule with containing a double bond, triple bond and an amine, what order should these priority groups be placed when naming the parent chain?

Answer 42

Alkene - Alkyne - Amine/Alcohol en-yn-amine/ol