Useful Chem Stuff

Front 1

Hydration

Back 1

phosphoric acid catalyst (H3PO4)
Alkene(g) + Steam --> Alcohol
eg. Ethene(g) + H20(g) --> Ethanol

Front 2

Halogenation

Back 2

RTP
Electrophilic Addition
Bromine molecule breaks by heterolytic fission
Alkene + Halogen --> Halogenoalkane
eg. Ethene + Bromine --> 1,2-dibromoethane

Front 3

Addition of Hydrogen

Back 3

catalyst is nickel
150 deg.c
alkene + h2 --> alkane
eg. ethene + h2 --> ethane

Front 4

Addition of Hydrogen Halides

Back 4

Gases at RTP
bubbled into liquid alkanes
eg. Ethene + HBr --> Bromoethane
HBr bond breaks by heterolytic fission

Front 5

Making Ethanol

Back 5

Hydration of ethene
Fermentation

Front 6

Hydration of Ethene

Back 6

phosphoric acid catalyst (H3PO4)
300 deg.C, 60 atm
Ethene (g) + H2O (g) --> Ethanol (l)

Front 7

Fermentation

Back 7

catalyst is zymase (enzyme in yeast)
37 deg.C (denatures any higher)
C6H12)6 (aq) --> 2CH3CH2OH (aq) + 2CO2 (g)
glucose --> ethanol + carbon dioxide

Front 8

uses and properties of methanol

Back 8

clean-burning fuel
used in high performance racing cars
smells like ethanol
extremely toxic
feedstock for chemical industry
can be converted to methanal and ethanoic acid

Front 9

uses of ethanol

Back 9

alcoholic beverages
perfumes, aftershaves, cleaning fluids
being developed as an alternative to petrol to fuel cars

Front 10

properties of alcohols

Back 10

hydrogen bonds
relatively high boiling points
low volatility
dissolve in water
solubility decreases as chain length increases (larger part of molecule made up of a non-polar hydrocarbon chain, hydrocarbon chain does not form hydrogen bonds with water molecules)

Front 11

oxidation of alcohols

Back 11

primary and secondary can be oxidised using an oxidising agent
oxidising agent is potassium dichromate (K2Cr2O7) or sulfuric acid (H2SO4)
changes colour from orange to green

alcohol + oxidising agent --> aldehyde + H2O (primary, distil immediately)
alcohol + oxidising agent --> carboxylic acid + H2O (primary, reflux)
alcohol + oxidising agent --> ketone + H2O (secondary, heat)

Front 12

dehydration of alcohols

Back 12

elimination reaction
catalyst is concentrated phosphoric acid (H3PO4) or concentrated sulfuric acid (H2SO4)
heated under reflux for ~ 40 mins
alcohol --> alkene + H2O

Front 13

esterification

Back 13

catalyst is concentrated sulfuric acid
alcohol warmed with carboxylic acid to produce ester
eg. propanoic acid + methanol --> methyl propanoate + H2O
OH bond on carboxylic acid broken, H on alcohol removed, OH + H --> H20
used as adhesives and solvents, perfumes and food flavourings

Front 14

hydrolysis of halogenoalkanes

Back 14

nucleophilic substitution
reflux
halogenoalkane reacts with hot hydroxide ions (commonly aqueous sodium hydroxide)
eg. 1-chloropropane (aq) + OH- (aq) --> propan-1-ol (aq) + Cl- (aq)

Front 15

reactivity of halogenoalkanes

Back 15

electronegativity of halogens decrease down the group
C-F is more electronegative than C-I
bond enthalpies decrease down the group
bond enthalpies have a bigger effect than polarity therefore rate of hydrolysis increases down the group (bonds broken more easily)

Front 16

radical polymerisation

Back 16

200 deg.c + high pressures
leads to branching of polymer chain
e.g poly(styrene)

Front 17

ziegler-natta process

Back 17

catalyst - TiCl3 or Al(C2H5)2Cl
60 deg. c

Front 18

catalytic converter

Back 18

made from platinum, rhodium, palladium on a honeycomb mesh (large surface area).

Front 19

mintreal protocol

Back 19

protects ozone layer

Front 20

stockholm convention

Back 20

encourage governments to eliminate/reduce release of toxic POPs (persistent organic pollutants)