Chemistry Unit 4

haloalkane to amine

substitution; add 2 ammonia; ethanol, heat, sealed tube

haloalkane to alcohol

substitution; add strong base; heat

alcohol to haloalkane

substitution; add hydrogen halide; heat, zinc chloride catalyst if substituting with HCl

alcohol to haloalkane

substitution; add hydrogen halide; heat, zinc chloride catalyst if substituting with HCl

alkane to haloalkane

substitution; add halide pair; UV light or 200ºC heat

alkene to dihaloalkane

addition; add halide pair; no conditions

alkene to haloalkane

addition; add hydrohalide; no conditions

alkene to alcohol

addition; add water; strong acid, 60atm, 300ºC heat

alkene to alkane

addition/reduction; add hydrogen gas; finely divided nickel, platinum or palladium catalyst and 150-300ºC heat

alkene to polyalkane

addition; adds several monomers of the alkene; heat, pressure and catalyst

haloalkane to alkene

elimination; add strong base; ethanol, heat

alcohol to alkene

elimination; ; strong acid, heat

primary alcohol to aldehyde

oxidation; ; sulfuric acid, potassium permanganate/dichromate and 50ºC heat

aldehyde to carboxylic acids

oxidation; ; sulfuric acid, potassium permanganate/dichromate and 50ºC heat

secondary alcohol to ketone

oxidation; ; sulfuric acid, potassium permanganate/dichromate and 70ºC heat

alcohol and carboxylic acid to ester

esterification (condensation); ; sulfuric acid and 70ºC heat

ester to alcohol and carboxylic acid

hydrolysis; add water

carboxylic acid and amine to amide

amide synthesis (condensation); ; 100ºC heat

amide to carboxylic acid and amine

hydrolysis; add water

identification of carboxylic acids

add water — dissociates to have a low pH

identification of amines

add water - produces hydroxide ions which lowers pH

test to separate alkenes from alkanes

add bromine water (brown) - addition reaction will occur in the presence of alkenes, decolouring the solution

test to distinguish tertiary alcohols from primary and secondary

add potassium permanganate (purple) or dichromate (orange); primary and secondary alcohols will turn brown/green

low density polyethene

requires 100-300MPa, 300ºC heat; lots of branching

high density polyethene

low pressure, 60ºC heat, Zieger-Natta catalyst; not much brancing

effect of aromatic groups on polymer biodegradability

reduces it

three syllabus addition polymers

polyethene (H/LDPE), polypropene (PP), polytetrafluoroethane (PTFE)

three syllabus condensation polymers

polylactic acid (PLA), polyamide (nylon) and polyester (e.g. PET

atactic; syntactic; isotactic

random; alternating; only one side

bond connecting monosaccharides

ether/glycosidic

alpha/beta monosaccharides

hydroxyl group on the carbon next to the ether bond is below/above

key functional groups of amino acids that are non-polar; polar ion-forming; polar non-ion forming

alkane groups; amine or carboxyl groups; OH or SH groups (typically)

bonds connecting amino acids in a protein

amide/peptide

Haber process

requires nitrogen and hydrogen gas to form ammonia; 200atm, 400-500ºC, Fe catalyst

contact process

requires vanadium oxide (V₂O₅), 1.5atm, 400ºC heat to produce sulfur trioxide

ethanol production via fermentation

uses yeast to make ethanol from glucose, production stops after concentration of ethanol = ~13%

ethanol production via catalytic hydration

ethene is hydrated, requiring 60atm, strong acid, 300ºC heat

production of hydrogen gas (steam reforming)

add methane to water; requires 700-1000ºC heat, nickel or platinum catalyst

acidic hydrogen fuel cells (anode; electrolyte, cathode)

hydrogen gas oxidises; phosphoric acid; hydrogen ions and oxygen gas reduce

alkaline hydrogen fuel cells (anode; electrolyte; cathode)

hydrogen gas oxidises with hydroxide ions; aqueous hydroxide ions; oxygen gas reduces with water

identifying chloro- or bromoalkanes on mass spec

look for prominent M, M+2, M+4… peaks

distinguishing between mono- and di- chloro- and bromoalkanes on mass spec

monohaloalkanes will only have an M and M+2 peak, dihaloalkanes will have up to M+4

distinguishing between bromo and chloroalkanes on mass spec

chloroalkanes have a ~3:1 ratio of M:M+2; bromoalkanes have a ~1:1 ratio instead