alkenes

Question 1

describe the trend in boiling point in alkenes

Answer 1

as carbon chain gets longer
there are more london forces
: mp/bp gets higher

Question 2

are alkenes unsaturated/saturated and why

Answer 2

unsaturated hydrocarbon
contains at least one c=c double bond

Question 3

what is the general formula of alkenes

Answer 3

CnH2n

Question 4

what is the exception for the general formula of alkenes

Answer 4

cyclic alkenes have 2 less hydrogens
CnH2n-2

Question 5

where do reactions occur in alkenes and why

Answer 5

they occur at the pi bond because pi bond is weak (electronegativity is spread over a wider distance)

Question 6

how to name an alkene

Answer 6

no. of Cs - no. C = is on - ene

Question 7

how to name an alkene with another element on it

Answer 7

no. its on - x no. of Cs - no. = is on - ene

Question 8

how do you draw alkenes

Answer 8

on a horizontal slant

Question 9

when do E Z isomers occur

Answer 9

if the groups bonded to each carbon atom in the C=C bond are different

Question 10

what do E isomers look like

Answer 10

sideways z

Question 11

what do z isomers look like

Answer 11

a bathtub

Question 12

describe an E isomer

Answer 12

trans isomer
groups not same on either side at double bond

Question 13

describe Z isomer

Answer 13

cis isomer
groups same on either side at double bond

Question 14

what are the rules of EZ isomers

Answer 14

both sides of double bond have to contain 2 different side chains

Question 15

what is ule 3 of EZ isomers

Answer 15

looing t position of top/bottom of priority across double bond
if they are same side (e.g. both top then Z)

Question 15

what is rule 2 of EZ isomerism

Answer 15

we assign priority groups on each side at double bond by atomic number

Question 16

define free radicals

Answer 16

A species with an unpaired electron

Question 17

define electrophile

Answer 17

species that accepts a pair of electrons from a nucleophile to form a bond

Question 18

define nucleophile

Answer 18

species that donate a pair of electrons
shown at Nu:

Question 19

define an addition reaction

Answer 19

2 reactants added together to form one product

Question 20

define substitution reaction

Answer 20

2 reactants to -> 2 products
Swapped over atoms from one reactant to another

Question 21

define an elimination reaction

Answer 21

Start with 1 reactant and take something out of it, forming 2 products
Often taking away water

Question 22

define redox reaction

Answer 22

Involves colour changes often - from reactant inorganic substance that is reduced
Tend to see it with alcohol going to carboxylic acids

Question 23

define organic oxidation

Answer 23

gain of oxygen/loss of hydrogen

Question 24

define organic reduction

Answer 24

loss of oxygen/gain of hydrogen

Question 25

define homolytic fission

Answer 25

breaking covalent bond between halogen producing free radical

Question 26

define heterolytic fission

Answer 26

pair of electrons from the covalent bod moves individual element gains electron from covalent bond and one element loses electron in covalent bond (the element is a halogen)

Question 27

what do curly arrows show

Answer 27

movement of pairs of electrons can be pair on element, can move into covalent bond

Question 28

what is Markovnikov's rule

Answer 28

Alkene addition mechanism: Intermediate that has our positive carbon (carbocation) determines the stable carbocation

Question 29

according to Markovnikov's rule,

Answer 29

Stability occurs when the carbocation has the most number of "C's" around it

Question 30

what kind of product is the more stable carbocation product

Answer 30

major product

Question 31

what kind of product is the less stable carbocation product

Answer 31

minor product

Question 32

how do you turn an alcohol into a haloalkane

Answer 32

with sodium halide and H2SO4

Question 33

how to turn a haloalkane into alcohol

Answer 33

add NaOH and reflux

Question 34

how to turn alcohol into an alkene

Answer 34

with concentrated H2SO4

Question 35

how to turn an alkene into alcohol

Answer 35

hydration of alkene add H2O (g) and H3PO4 catalyst

Question 36

how to turn an alkene into a haloalkane

Answer 36

add hydrogen halide

Question 37

how to turn an alkene into an alkane

Answer 37

hydrogenate the alkene with H2 and a Ni catalyst at 432K

Question 38

how to turn an alkane into a haloalkane

Answer 38

using a halogen or UV

Question 39

what could happen with hydration of alkenes when attempting to form alcohols

Answer 39

multiple products with asymmetrical alkenes

Question 40

what are the two different types of polymerisation

Answer 40

addition - alkanes condensation

Question 41

what is the general reaction for polymers forming from alkenes

Answer 41

alkene double bond broken by high temp and pressure and forms a polymer

Question 42

what are the pros of using polymers to store food and chemicals

Answer 42

they are very unreactive

Question 43

what are the pros of recycling polymers -2

Answer 43

reduces environmental impact by conserving finite fossil fuels decreasing the amount of waste going to landfill

Question 43

what are the problems with disposing of polymers

Answer 43

lots are non-biodegradable they build up in the environment, damaging it - killing marine wildlife

Question 44

describe the stages of polymers being recycled

Answer 44

sort polymers into types chopped into flakes washed, dried and melted cut into pellets and used my manufacturers

Question 45

what is the issue with PVC recycling

Answer 45

it is hazardous due to high chlorine content and additives dumping PVC in landfill isn't sustainable

Question 46

how are waste polymers used as fuels

Answer 46

polymers that are derived from petroleum or natural gas have a high energy stored value making them difficult to recycle Waste polymers can be incinerated to produce heat, generating steam to drive a turbine to produce energy

Question 46

what happens when PVC is burnt

Answer 46

it releases hydrogen chloride a corrosive gas and other toxins like dioxins

Question 47

what is feedstock recycling

Answer 47

The chemical and thermal processes that reclaim monomers, gases or oil from waste polymers

Question 47

how has new technology changed how PVC is dealt with

Answer 47

previously: grinding PVC and using it to manufacture new products now: dissolves polymer using solvents - then recovered by precipitation from the solvent, then solvent is used again

Question 48

what are the products of feedstock recycling

Answer 48

they resemble those produced from crude oil refineries These materials can be used as raw materials for the production of new polymers

Question 49

what is an advantage of feedstock recycling

Answer 49

it is able to handle unsorted and unwashed polymers

Question 50

what are the pros of biodegradable polymers 2

Answer 50

protects our environment conserves valuable oil reserves

Question 51

what are biodegradable molecules

Answer 51

Bioplastics produced from plant starch, cellulose, plants oils, and proteins offer a renewable and sustainable alternative to oil-based products

Question 52

what are photodegradable polymers

Answer 52

polymers contain bonds that are weakened by absorbing light to start the degradation. Alternatively, light-absorbing additives are used