organic reactions

Question 1

Addition reactions

Answer 1

• unsaturated molecule breaking to form a saturated molecule

Alkene/Alkyne breaking to form an alkane

Question 2

substitution reactions

Answer 2

Replacing an atom/group with another group.
* adding something to a molecule AND
* there is a leaving group (taking something out)

Question 3

elimination reactions

Answer 3

*saturated compounds becomes unsaturated by removal of 2 atom/ group of atoms.

alkanes becoming alkenes.

Question 4

What are the 4 addition reactions

Answer 4

1. Hydrogenation
2. Halogenation
3. Hydrohalogenation
4. Hydration

Question 5

What are the 3 Substitution reactions

Answer 5

• all single bonds (saturated)

1. Hydrolysis (forming an alcohol)
2. Forming of a haloalkane + acid
3. Forming of a haloalkane + water

Question 6

What are the 2 elimination reactions?

Answer 6

1. Dehydration
2. Dehydrohalogenation

Question 7

Hydrogenation

Answer 7

addition of a H2
catalyst: Pt or Pd. (heat) / metal catalyst

Alkene + H2 → Alkane
Alkyne + H2 → Alkene

• Forward rxn = reduction (addition)
• Reverse rxn = oxidation ( elimination)

Question 8

Halogenation

Answer 8

addition of a X2
catalyst: none, the halogen bonds are weak

Alkene + X2 → Haloalkane

radical substitution reaction

Question 9

Acid catalyzed Hydration

Answer 9

addition of water
Catalyst: strong acid/an acid catalyst

Alkene + H2O → Alcohol

Question 10

Hydrohalogenation

Answer 10

Alkene + HX → Haloalkane

• addition of an acid
• catalyst: none
  no water must be present

Question 11

Hydrolysis- formation of an alcohol
(substitution with a haloalkane)

Answer 11

haloalkane + H20 → Alcohol + Acid

haloalkane + strong base → alcohol + salt

Question 12

formation of a haloalkane + acid

Answer 12

catalyst: light

Alkane + X2 → haloalkane + Acid

Question 13

formation of a haloalkane + water
(Substitution with an alcohol)

Answer 13

Alcohol + HX → Haloalkane + H2O

Question 14

Acid catalyzed Dehydration
(elimination with an alcohol)

Answer 14

catalyst: strong acids and high temperatures

Alcohol → Alkene + H2O

Question 15

dehydrohalogenation
(elimination with haloalkane)

Answer 15

concentrated strong base

haloalkane + Strong base → Alkene + salt + H2O

Question 16

alkenes/ Alkynes undergo

Answer 16

addition reactions
- substitution and elimination are less important in unsaturated systems

Question 17

reduction reaction

Answer 17

whenever you add H to an organic compound
- Aldehydes and ketones are reduced to alcohols
- reducing agents: LiAlH4 and NaBH4

Question 18

oxidation reaction

Answer 18

whenever you remove H from an organic compound
- Aldehydes are easily oxidized to carboxylic acids
- ketones resist oxidation

Question 19

why do you need a acid (H+) catalyst for hydration reactions?

Answer 19

because water is a poor electrophile, in fact it is a nucleophile

Question 20

Electrophilic carbons

Answer 20

• haloalkanes
• Alcohols
• Ethers
• Amines

Question 21

nucleophilic carbons

Answer 21

• organometallic

Question 22

what is an alkyl halide?

Answer 22

organic molecules containing a halogen atom bonded to an sp3 hybridized carbon atom

Question 23

for haloalkanes what reactions do we expect to see?

Answer 23

substitution or elimination

Question 24

what favours substitution?

Answer 24

-low temperatures
- small nucleophiles (attack the carbon inside the molecule)
- absence of steric hinderance (small H atoms around carbon centers)

Question 25

what favours elimination?

Answer 25

- high temperature- larger nucleophiles (attack the hydrogen on the surface of the molecule) - crowded carbon center ( bigger groups around carbon) * any hinderance favours elimination

Question 26

Alcohols

Answer 26

- require an H (acid) catalyst to drive the reaction forward

Question 27

an alcohol can also undergo an oxidation reaction (also a type of elimination reaction) but an oxidant is required. What are they?

Answer 27

- K2Cr2O7: potassium dichromate - KMnO4: potassium permanganate - CrO3: chromium trioxide - H2CrO4: chromic acid - PCC : pyridinium chlorochromate

Question 28

if the alcohol being oxidized is a 1° alcohol we will get...

Answer 28

- a carboxylic acid or - aldehyde

Question 29

if the alcohol being oxidized is a 2° alcohol then we get...

Answer 29

a ketone

Question 30

if the alcohol being oxidized is a 3° alcohol then we get...

Answer 30

no reaction as they DO NOT OXIDIZE

Question 31

are Ethers reactive or not?

Answer 31

not reactive as they are unusually stable

Question 32

Amines

Answer 32

- basic and - nucleophilic

Question 33

Nucleophiles can either be neutral or be negatively charges. How do these react?

Answer 33

- neutral - requires an acid catalyst - negatively charged - no catalyst required

Question 34

nucleophilic addition

Answer 34

- a good nucleophile attacks first ( it will attack the carbon atom - the electrophile)

Question 35

composite functional groups and the type of reaction they undergo?

Answer 35

* these all have the double bonded O - carboxylic acids - Esters - Amides - Acid chlorides ** These reactions undergo substitution

Question 36

ketones are reduced to?

Answer 36

secondary alcohols

Question 37

carboxylic acids are reduced to?

Answer 37

primary alcohols

Question 38

aldehydes are reduced to?

Answer 38

primary alcohols

Question 39

alkyl halides have what type of hybridization? (haloakanes)

Answer 39

sp3

Question 40

Benzene? aromatic compounds do not undergo ______ reactions even though there are double bonds. Due to its stability it would rather undergo ______ reaction

Answer 40

addition substitution (electrophilic sub)

Question 41

Halogenation of benzene

Answer 41

requires an acid catalyst like FeBr3 or AlCl3

Question 42

Friedel crafts alkylation

Answer 42

Uses alkyl halides as reactants.

Question 43

Friedel crafts acylation

Answer 43

Uses acyl halides as reactants, the double bonded oxygen with a Cl2

Question 44

condensation polymerization

Answer 44

molecules are joined by the elimination of a small molecule (water)

Question 45

addition polymerization

Answer 45

monomers must be an alkenea

Question 46

acidic amino acids

Answer 46

have 2 carboxylic acid parts

Question 47

basic amino acids

Answer 47

2 amine parts

Question 48

non polar hydrophobis amino acids

Answer 48

has a benzene

Question 49

polar hydrophilic amino acid

Answer 49

have OH groups

Question 50

Aerosol

Answer 50

a colloid with a liquid/solid dispersed in a gas - e.g fog, mist, smoke

Question 51

Foam

Answer 51

colloid with a gas dispersed in a liquid/ solid - e.g. whipped cream

Question 52

gel

Answer 52

colloid with a solid dispered in a liquid - e.g. clue, paint, blood, gelatin

Question 53

emulsion

Answer 53

a liquid substance dissolved in a liquid medium where two immiscible liquids form a colloid held together by an emulsifying agent.

Question 54

sol

Answer 54

when a solid substance is dispersed in a solid mediumamp

Question 55

amphiphilic

Answer 55

contains both a hydrophobic tail and a hydrophilic head

Question 56

conformational isomers

Answer 56

- single bonds - free rotation around these bonds - staggered (low energy) / eclipsed (high energy)

Question 57

Geometric isomers

Answer 57

- require double/ triple bonds/ ring structures - no rotation -cis/ trans

Question 58

enantiomers

Answer 58

- require sp3 hybridized carbons with 4 different substituents (chiral centers) - NON SUPERIMPOSABLE MIRROR IMAGES