organic chem

• Hydrogenation:

  Alkene reacting + hydrogen -> alkene

                                               150 degrees

                                                  Nickel catalyst
• Hydration

  Reacting w water

  Alkene + water (steam)  ⇌  alcohol

                                                      300 degrees

                                                          70 atm

                                                           Phosphoric catalyst
• Reaction w halogens

  Ethene + chlorine -> dichloroethane
• Alcohols

  -fuels

  -solvents

  -alcoholic drinks
• Ways of making alcohols:

  1)hydration

  2)fermentation of sugar
• Fermentation:

  Glucose                 ->        alcohol(ethanol) + carbon dioxide

                                    Yeast

                                    30 degrees

                                     Anaerobic conditions
•  

  Alcohols :

  -soluble in water

  -as no. of carbon atoms increase, solubility decreases

   

  Alcohols + sodium -> sodium (insert no of carbons)oxide + hydrogen

                                                                   Eg sodium methoxide

   
• Reaction with oxidising agent:

  Alcohol -> carboxylic acid + water    eg:

   

  Ethanol     ->   ethanoic acid  + water

                 Oxidising agent
• Carboxylic acids:

  Weak acids, in water

   

  CH3COOH ⇌ CH3OOO-  + H+

  Ethanoic acid is ionising to produce the ethanoate ion and H+

  Carboxylic acids only partially ionise in aqueous solution they are weak acids

  Carboxylic acids have a higher pH than HCl

   
• Reaction with metal carbonate:

  Ethanoic acid + sodium carbonate -> sodium ethanoate + carbon dioxide + water
• Carboxylic acid + alcohol ⇌  ester
• Ethanoic acid + ethanol     ⇌       ethyl ethanoate

                                                    Sulfuric acid catalyst
• Addition polymers

   

  Monomers are alkenes

  Double carbon bond splits in polymer
• Condensation polymers

   

  Lose water

  Start with 2 different monomers

  Each monomer has 2 of the same functional groups
• Amino acids

  Condensation polymerisation to make polypeptide

  Aine group + carboxylic group

  Nh2         +          cooh
• DNA

   

  Naturally occurring polymer

  2 polymer chains DOUBLE HELIX!!!

  Monomer called nucleotides
• Naturally occurring polymers

  Proteins -> polymers of amino acids

  Starch -> polymers of glucose

  Cellulose-> polymers of glucose
• ALLOYS

  Bronze = copper + tin -statues doesn’t usually corrode

  Brass =  copper + zinc-instruments door handles

  High carbon hard but brittle chisels

  Low carbon steel is softer + more easily shaped used for car bodies

  Stainless stell – chromium + nickel

  Aluminium low density -aeroplanes
• CERMANICS

  Most glass we use is soda lime glass – windows bottles

  Sand sodium limestone melt until melts when cool sit solidifies

  But low melting point limiting its uses
• Borosilicate glass higher melting point than soda lime useful for objects that require heating kitchenware and labware

  Melting sand and boron trioxide
• Clay ceramics

  Pottery bricks

  Uses clay minerals we find in the ground

  When wet can be shaped, then heated in a furnace to harden
• Composites:

  Made from combining 2 diff materials

  Reinforcement which consists of fibres or fragments of one material

  Reinforcement is then surrounded by a matrix or binder material

  Composites have diff properties to the materials in them

  Eg carbon fibre composite reinforcements material are fibres of carbon and matrix is plastic resin

  Carbon fibre is v strong and light making it v useful eg in cars or aircraft parts
• Thermosofteing polymers melt when heated

  Can reshape when soft solid when cooled back down

  Held by intermolecular forces when heated they break

  Then polymer strands can separate from each other and polymer melts
• Thermosoftening vs thermosetting

  Properties of polymers depend on the monomer and condition it was made in
• Thermosetting polymers don’t melt when we heat them

  Polymer chains connected tg with strong crosslinks

  These strong cross links are not broken by heat so don’t melt when heated
• HARBER PROCESS

  Fertilisers

  Ammonia produces

  Nitrogen + hydrogen  ⇌    ammonia

  Nitrogen extracted from  air

  Hydrogen produced from heating methane w steam

  Purified nitrogen and hydrogen are passed over an iron catalyst at 450 degrees + 200 atm

  Reversible reaction so some ammonia breaks down into n and h

  To increase yield we cool the ammonia to turn it into a liquid which is removed

  Recycle unreacted nitrogen and hydrogen back over the catalyst
• HARBER PROCESS CONDITIONS

  High temp = more E and £

  Low temp = high yield but slow ROR

  High temp = fast ROR but low yield

  Forward is exo, a cool temp will shift equilibrium to right side

  But cool temp makes reaction slow trade off between ROR and position of eq.

  450 is a compromise with relatively fast rate and relatively high yield of ammonia

  Iron catalyst increases ROR no effect on eq.

  Yield of ammonia is high at v high pressure but v dangerous and expensive

  High pressure pushes eq. to right
• NPK FETRILISERS

  Nitrogen

  Phosphorus

  Potassium

  Make plays grow larger + faster

  Formulation of diff salts
• Nitrogen – main compound ammonium nitrate

  Use ammonia from harber process use ammonia to make nitric acid

  React nitric acid with more ammonia to make ammonia nitrate
• Potassium comes from salts potassium chloride or potassium suphate

  Both mined from ground

  Can be used wo  further processing
• Phosphorus in phosphate rock

  Has to be chemically processed before being used in fertilisers

  Treating rock w nitric acid = phosphoric acid + calcium nitrate

  Phosphoric acid contains phosphorus but cannot add this directly to plants so neutralise w ammonia

  Produces ammonium phosphate which can be used in NPK fertiliser

  Treating phosphate rock w sulfuric acid makes mixture of calcium phosphate and calcium sulphate

  Mixture called single superphosphate ad can be used in NPK fertilisers

  Treating phosphate rock w phosphoric acid we make triple superphosphate can be found in NPK fertilisers
• Ammonium nitrate

  Produced by reacting ammonia with nitric acid which is a neutralisation reaction