Core Organic Chemistry

Question 1

What’s a homologous series?

Answer 1

A series of compounds with similar chemical properties whose successive members differs by the addition of a -CH2- group.

Question 2

What’s a functional group?

Answer 2

The part of molecule responsible for the chemical properties.

Question 3

Aliphatic

Answer 3

carbon atoms arranged in line (branched or unbranched)

Question 4

Alicyclic

Answer 4

carbon atoms arranged in a ring (branched or unbranched)

Question 5

Aromatic

Answer 5

carbon atoms mostly arranged in a benzene ring

Question 6

Suffix for aldehyde & ketone

Answer 6

Aldehyde: -al
Ketone: -one

Question 7

Structural isomerism

Answer 7

Same molecular formula but different structural formula

Question 8

Homolytic fission

Answer 8

Each atom has a single electron
Radicals are formed

Question 9

Heterolytic fission

Answer 9

One atom takes both electrons
Negative & positive ions are formed

Question 10

Addition reaction

Answer 10

2 reactants form 1 product

Question 11

Substitution reaction

Answer 11

An atom/group is displaced by a more reactive atom/group.

Question 12

Elimination reaction

Answer 12

Removal of small molecule from bigger one. 1 reactant makes 2 products

Question 13

General formula for alkanes

Answer 13

CnH2n+2

Question 14

General formula for alkenes

Answer 14

CnH2n

Question 15

General formula for alkynes

Answer 15

CnH2n-2

Question 16

General formula for alcohols

Answer 16

CnH2n+1OH

Question 17

General formula for haloalkanes

Answer 17

CnH2n+1X (X is a halogen)

Question 18

General formula for carboxylic acids

Answer 18

CnH2n+1COOH

Question 19

General formula for aldehydes

Answer 19

CnH2nO

Question 20

General formula for ketones

Answer 20

CnH2nO

Question 21

Bond angles and arrangement for alkanes

Answer 21

109.5º
Tetrahedral

Question 22

Why does boiling point of alkanes increase as chain length increases?

Answer 22

• Larger surface area
• More contact
• More London forces
• Stronger bonds

Question 23

Why do branched alkanes have lower boiling point?

Answer 23

• Branches allow for less contact area
• Less London forces
• Weaker bonds

Question 24

Combustion of alkanes

Answer 24

Alkane + Oxygen –> Carbon dioxide + water

Question 25

Incomplete combustion of alkanes

Answer 25

Form water and carbon monoxide/carbon

Question 26

Reaction of alkanes with halogens

Answer 26

Alkane + Halogen –> Haloalkane + hydrogen halide
- Needs sunlight (UV)

Question 27

Stages of radical substitution

Answer 27

1) Initiation
2) Propagation
3) Termination

Question 28

Initiation (Radical substitution)

Answer 28

• Halogen covalent bond broken by homolytic fission
• Forms radicals
• Needs sunlight (UV)

Question 29

Propagation (Radical substitution)

Answer 29

1) - Br radical reacts with C-H bond
- Forms CH3 radical and HBr
2) - CH3 radical reacts with Br, forming CH3Br, and Br radical

Question 30

Termination (Radical substitution)

Answer 30

2 radicals collide forming a molecule with all electrons paired

Question 31

Shape & angle around a double bond

Answer 31

Trigonal planar (120º)

Question 32

Stereoisomers

Answer 32

Same structural formula but different arrangements of atoms

Question 33

E/Z isomerism

Answer 33

E Isomerism: Different sides
Z Isomerism: Same sides

Question 34

Cis-Trans isomerism

Answer 34

Same as E/Z isomerism, but hydrogen is attached to carbon

Question 35

Hydrogenation of alkenes

Answer 35

Alkene + hydrogen –> Alkane

Question 36

Halogenation of alkanes

Answer 36

Alkene + halogen –> Haloalkane

Question 37

Testing for unsaturation (double bond)

Answer 37

Add bromine water to substance,
if it turns colorless, it has a double bond

Question 38

Alkenes + hydrogen halides

Answer 38

Alkenes + hydrogen halides –> Haloalkane

Question 39

Hydration of alkenes

Answer 39

Alkene + steam –> alcohol

Question 40

Electrophiles

Answer 40

• Positive charge
• Attracted to electron-rich region
• Accepts electrons

Question 41

Nucleophile

Answer 41

• Negative charge
• Attracted to electron-deficient region
• Donates electrons

Question 42

Electrophilic addition mechanism

Answer 42

1) Bond donates 2 electrons to Hydrogen in HBr, H-Br bond electrons go to Br
2) Carbocation is formed, Br reacts with it
3) haloalkane is formed

Question 43

Markownikoff’s rule

Answer 43

Major product: Secondary carbocation
Minor product: Primary carbocation

Question 44

Carbocation stability

Answer 44

Stability increases In increasing carbocation classification
Primary < Secondary < Tertiary

Question 45

Polyethene

Answer 45

Plastic bags, bottles, toys

Question 46

Poly(chloroethane)

Answer 46

Pipes, bottles, sheets…
Can be rigid or flexible

Question 47

Disposing methods of polymers

Answer 47

• PVC Recycling
• Using polymers as fuels
• Feedstock recycling (obtain raw materials)

Question 48

Bioplastics

Answer 48

• Photodegradable
• Biodegradable

Question 49

Alcohols vs Alkanes

Answer 49

• Higher melting points
• Less volatile
• Greater solubility

Question 50

Why do alcohols have stronger bonds

Answer 50

• Polar bonds
• Hydrogen bonds

Question 51

Primary alcohol

Answer 51

carbon attached to 1 alkyl group

Question 52

Secondary alcohol

Answer 52

carbon attached to 2 alkyl groups

Question 53

Tertiary alcohol

Answer 53

carbon attached to 3 alkyl groups

Question 54

Combustion of alcohols

Answer 54

Alcohol + Oxygen –> Carbon dioxide + water

Question 55

Oxidation of primary alcohols

Answer 55

• Can form aldehyde (distillation)
• Can form carboxylic acids (reflux)

Question 56

Oxidation of secondary alcohols

Answer 56

Oxidized to ketones

Question 57

Dehydration of alcohols

Answer 57

Alcohol –> Alkene + water
- acid catalyst
- reflux

Question 58

Substitution reaction of alcohols

Answer 58

Alcohol + hydrogen halide –> haloalkane + water

Question 59

Nucleophilic substitution

Answer 59

halogen is substitution by nucleophile in haloalkane

Question 60

Hydrolysis of haloalkanes

Answer 60

Haloalkaanes –> Alcohols