organic chemistry

Question 1

homologus series

Answer 1

a family of compounds with similar chemical properties where each successive member differs by an addition of a CH2 group

Question 2

functional group

Answer 2

part of the organic molecule responsible for its chemical reactivity

Question 3

structural isomerism

Answer 3

molecules with the same molecular formula but a different structural formula

Question 4

stereoisomerism

Answer 4

molecules with the same structural formula but a different arrangement of atoms in space

Question 5

what is a priority group?

Answer 5

the group attached to a carbon with the highest atomic number

Question 6

z isomer

Answer 6

if the priority groups are on the same side as each other

Question 7

e isomer

Answer 7

if the priority groups are on the opposite sides of each other

Question 8

cis/trans isomerism

Answer 8

applies if each carbon is bonded to a hydrogen

Question 9

cis isomer

Answer 9

whether the priority groups are on the same side

Question 10

trans isomer

Answer 10

if the priority groups are on a different side to each other

Question 11

how do you know if a molecule has stereoisomerism

Answer 11

• must have a double bond
• each carbon in the double bond must be bonded to two different groups
• for cis/trans, each carbon in the double bond must be bonded to one hydrogen

Question 12

list alkene reactions

Answer 12

hydrogenation
hydration
halogenation
hydrogen halides
additional polymerasation

Question 13

what catalyst do you use in a hydrogenation reaction and at what temp?

Answer 13

nickel at 150 degrees / 423k

Question 14

what catalyst do you use in a hydration reaction

Answer 14

hydrogen phosphate (H3PO4)

Question 15

define electrophile

Answer 15

an electron pair acceptor

Question 16

mechanism name of halogenation for alkenes

Answer 16

electrophilic addition

Question 17

mechanism name for halogenation of alkanes

Answer 17

free radical substitution

Question 18

mechanism for hydrogen halides

Answer 18

electrophilic addition

Question 19

polymer

Answer 19

long chain molecules found from many repeat units of monomers eg polyethene

Question 20

monomer

Answer 20

a small molecule that combines with many other monomers to form a polymer eg ethene

Question 21

additional polymerasation

Answer 21

formation of polymers by repeated addition reactions of many unsaturated alkane molecules (monomers)

Question 22

feedstock recycling

Answer 22

breaking polymer down into small molecules which allow them to be used to make something else

Question 23

why are alcohols soluble in water?

Answer 23

because they form hydrogen bonds with water

Question 24

why are alchohols less volatile?

Answer 24

• less volatile and a higher b.p. than the corresponding alkane because they turn into gas quicker and for h2 bonds unlike other alkanes which requre more energy to break

Question 25

fermentation of sugars

Answer 25

C6H12O6 -------> 2C2H5OH + 2CO2

Question 26

oxidising agent for alcohols

Answer 26

K2Cr2O7 / H2SO4

Question 27

what do primary oxidation alcohols form and what conditions do they use?

Answer 27

they form an aldehyde (prefix - al) and go under distillation

Question 28

if primary oxidation uses reflux what does it form

Answer 28

carboxylic acid (prefix - oic)

Question 29

what do secondary oxidation alcohols form and what conditions do they use?

Answer 29

they form a kentone (prefix - one) and they use reflux conditions

Question 30

define nucleophile

Answer 30

an electron pair donor

Question 31

what does substitution of alcohols form

Answer 31

haloalkane + NaSO4 + water

Question 32

what is used in the substitution of alcohols

Answer 32

sodium halide + sulfuric acid

Question 33

what condition is used in the dehydration of alcohols?

Answer 33

reflux

Question 34

what happens as we increase the carbon chain length

Answer 34

- larger surface area - so more surface points of contact - more electrons - stronger london forces - more energy required to break the LFs - hence b.p. increases

Question 35

what happens as we increase the branching

Answer 35

- fewer surface points of contact - weaker london forces - less energy required to break the LFs - so b.p. decreases

Question 36

volatility meaning

Answer 36

turns into a gas very quickly

Question 37

why are alcohols very soluble in water?

Answer 37

because they form hydrogen bonds with water - alkanes are non-polar

Question 38

why are alcohols less volatile but have a higher boiling point than the corresponding alkane?

Answer 38

- alkanes turn into a gas quicker - since alcohols form hydrogen bonds, they are less volatile as they don't turn into a gas quickly since their hydrogen bonds require more energy to break than the London forces between the alkanes

Question 39

what's made from polyethene

Answer 39

- plastic straws - plastic bags - plastic bottles

Question 40

what's made from pvc (poly vinyl chloride)

Answer 40

- window frames - gutter pipes - cling film - laminated flooring

Question 41

what's made from polypropene

Answer 41

- bottle cap lids - children's toys eg lego

Question 42

what can be made from polystyrene

Answer 42

- styrofoam

Question 43

what can be made from PTFE (polytetrafluroethene)

Answer 43

- waterproof/burnproof coating eg on coats, pans, cars - insulating tape

Question 44

downside of burning pvc

Answer 44

releases tcl - a toxic gas

Question 45

what does hydrolysis of haloalkanes form?

Answer 45

haloalkanes + h20 ----> alcohol + hydrogen halide

Question 46

mechanism for substitution of haloalkanes

Answer 46

nucleophilic substitution

Question 47

nucleophile definition

Answer 47

an electron pair donor

Question 48

homolytic fission def.

Answer 48

the breaking of a covalent bond with one of the bonded electrons going to each atom, forming two radicals

Question 49

heterolytic fission def.

Answer 49

the breaking of a covalent bond forming a cation (+) and an anion (-)