Basic Organic - Alkanes And Alkenes

Question 1

Alkene

Answer 1

C=C -ene

Question 2

Alcohol

Answer 2

-OH hydroxy- /-ol

Question 3

Haloalkane

Answer 3

-halogen chloro- bromo- iodo-

Question 4

Aldehyde

Answer 4

-CHO -al

Question 5

Ketone

Answer 5

-C(CO)C- -one

Question 6

Carboxylic acid

Answer 6

-COOH oic acid

Question 7

Ester

Answer 7

-COOC- oate

Question 8

Acyl Chloride

Answer 8

-COCl -oyl chloride

Question 9

Amine

Answer 9

-NH2 amino- -amine

Question 10

Nitrile

Answer 10

-CN

Question 11

Molecular formula

Answer 11

Number and type in molecule
Eg C2H6O

Question 12

Empirical

Answer 12

Simplest whole number ratio
Eg C6H12O6= CH2O

Question 13

Displayed formula

Answer 13

Relative positions drawing bonds between atoms

Question 14

Structural formula

Answer 14

Arrangements of atoms in molecule
Eg CH3CH2CH2CH3

Question 15

Structural isomers

Answer 15

Compounds with the same molecular formula but different structural formulae
Isomers w same function group- same function group different position
Isomers w different func groups eg ketones and aldehydes

Question 16

Bond fission

Answer 16

Breaking covalent bonds
Homolytic or heterolytic fission

Question 17

Homolytic fission

Answer 17

Each take one of the shared paired electrons forming radical
Cl• for example

Question 18

Heterolytic fission

Answer 18

One of the bonded atoms take both electrons
Forms positive and negative ions

Question 19

Addition reactions

Answer 19

Two reactants join together to form one product

Question 20

Substitution

Answer 20

An atom or group of atoms are replaced

Question 21

Elimination

Answer 21

Removal of a small molecule from larger forming 2 products

Question 22

Alkanes

Answer 22

Used as fuel
CnH2n+2

Question 23

Bonding in alkanes

Answer 23

Saturated hydrocarbons held together via single covalent bonds
Covalent bonds= sigma bonds result of 2 overlapping orbitals
Bond angle is 109.5

Question 24

Boiling points in alkanes

Answer 24

Increase as chain length incr more electrons / greater sa therefore Greater London forces more energy required
Branched = lower bp fewer surface points of contact therefore London forces are weaker

Question 25

Alkane reactions

Answer 25

Don’t react with most due to sigma bond strength and non polar molecules/bonds Combustion forming CO2 and H2O Reaction with halogens using UV light

Question 26

Bro I nation of alkanes

Answer 26

1. Initiation- bromine molecule broken via Homolytic fission v reactive Br radicals 2. Propagation Br• reacts with a C-H bond forming •CH3 radical and HBr •CH3 reacts with Br2 and forms a new Br• 3. Termination- Br• form Br2 or •CH3 forms C2H6 or forms CH3Br

Question 27

Limitations of radical substitution

Answer 27

Further substitution takes place so difficult to form one organic compound Can substitute until CBr4 or form monosubstiuted isomers by sub at different positions in the chain

Question 28

Structure and bonding of Alkene

Answer 28

Unsaturated hydrocarbons CnH2n Sigma bonds and pi bonds 120 bond angle

Question 29

Pi bonds

Answer 29

Overlap of 2p orbitals one from each carbon involved in double bond Electron density is conc in this bond Prevents carbon atoms rotating

Question 30

Stereoisomers

Answer 30

E/z cis/trans Same structural formula different arrangement of atoms in space

Question 31

Cahn Ingold rules

Answer 31

If higher priority on the same side = z isomers If higher priority on different = e isomers Higher priority = higher atomic number

Question 32

Reactivity of Alkene

Answer 32

React more readily due to the bond enthalpy of Oi bond is weaker so broken more readily

Question 33

Addition reactions of Alkene

Answer 33

With hydrogen (nickel catalyst) Halogens Hydrogen halides Steam (acid catalyst)

Question 34

Electrophilic addition with Alkene a

Answer 34

Pi bond has high electron density which attracts electrophiles HBr + Alkene pi bond attracted to positive hydrogen breaks HBr breaks via heterolytic fission and Br- attracted to carbocation

Question 35

Markownikoffs rule

Answer 35

Secondary carbocation forms the major product in contrast to the primary as it is more stable

Question 36

Addition polymerisation

Answer 36

Monomer - Alkene Polymer - poly(Alkene) High temp and catalyst required

Question 37

Disposing of waste polymers

Answer 37

Lack of reactivity of polymers makes it hard to dispose and are non biodegradable Recycle- plastics chopped into flakes and reused PVC recycling - solvents dissolve Waste polymers as fuels