Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
64 Cards in this Set
- Front
- Back
|
acid + metal |
salt + hydrogen gas |
|
|
Acid + carbonate --> |
Carbon dioxide + water + salt |
|
|
Combustion: |
hydrocarbon + oxygen --> water + carbon dioxide |
|
|
Cracking of pentane |
Pentane --> ethylene + propane |
|
|
Cyclohexene + bromine + water |
2-bromo-1-cyclohexanol + hydrogen bromide |
|
|
Dehydration of ethanol: |
Ethanol --> (conc. H2SO4) ethylene + water |
|
|
Cracking |
process of 'breaking' long-chained hydrocarbon into smaller chains, using heat
|
|
|
Thermal Cracking conditions |
700-1000 degrees, no catalyst |
|
|
thermal cracking steps |
C10H22 --> 2C5H11Initiation: free radical produced, C5H11. --> C3H7. + C2H4 propagation: free radicals decompose to produce smaller free radicals which release ethylene, 2C3H7. --> C6H14termination: Hydrocarbon molecules reform when free radicals react with one another |
|
|
Catalytic cracking conditions |
absence of air, pressure above atmospheric, 500 degrees, presence of a catalyst composed of a zeolite (aluminium silicate) - which is porous such that cavities exist. Not sufficient |
|
|
Why is ethylene so reactive |
unsaturated bonds (double-bonds): readily splits open creating 2 new bond positions. Can undergo polymerisation and addition reactions |
|
|
Cyclohexane + bromine water results |
bromine transferred into the alkane as bromine is non-polar so would prefer to dissolve in a non-polar substance - the orange colour transferred to top liquid (cyclohexane is less dense than water) |
|
|
Cyclohexene + bromine water results |
the bromine is added to the bonds in the alkene - therefore decolourised |
|
|
Polymerisation |
chemical reaction in which small, identical molecules (monomers) to form one very large molecule (polymer) |
|
|
Addition polymer |
Formed by joining individual monomers without the loss of any atoms. e.g. polyethylene. |
|
|
Polyethylene 2 ways of production |
High pressure method - Low density polyethylene Zieger-Natta process - high density polyethylene |
|
|
High Pressure method |
Low density polyethylene: 1000-3000 times atmospheric High temperatures (300) Initiator (organic peroxide - contains o-o group) Chain branching Flexible, soft and clear |
|
|
Zieger-Natta process |
High Density Polyethylene Forms unbranched polyethylene Linear chains crystalline Catalyst of zieger-natta pressure just higher than atmospheric Temp - 60 degrees Harder plastic |
|
|
Vinyl Chloride (common name) - what is the systematic name, makeup and name of polymer |
Chloroethene - an ethylene molecule with one chlorine atom substituting hydrogen atom - polymer: polyvinyl chloride (PVC) |
|
|
Styrene (common name) - what is the systematic name, makeup and name of polymer |
Phenylethene (phenyl-benzene) - One hydrogen atom replaced by a benzene ring - polymer: polystyrene |
|
|
Low-density Polyethylene Properties and Use |
- flexible, clear and non-toxic (branching - weaker bonds, lower MP and density) - plastic bags, plastic cling wrap, milk bottles |
|
|
High-density polyethylene Properties and Use |
- Strong and non-toxic, rigid, slightly flexible, unreactive - kitchen utensils and containers, rubbish bins, buckets |
|
|
Polyvinyl Chloride (PVC) Properties and Use |
- Dispersion forces increase with molecular weight - flexible and durable, softened with plasticisers, can contain UV inhibitors, rigid and hard, unreactive, easily shaped - Garden hoses, electrical insulation, drainage, sewerage, pipes |
|
|
Crystal Polystyrene Properties and Uses |
Dispersion forces, clear, hard, rigid, inflexible, easily shaped and a good insulator, durable - CD cases, screw driver handles
|
|
|
Expanded Polystyrene Properties and Uses |
- light and fluffy, insulator but still hard and rigid - hot cups, insulation and packaging |
|
|
Condensation polymer |
formed by joining monomer molecules by eliminating a small molecule (usually water) The functional groups of the two monomers react together P |
|
|
Polymerisation of glucose |
2 - hydroxyl groups on the first and forth carbons forming a glycosidic bond (C-O-C) |
|
|
Biopol |
Polyhdroxyalkanoate (PHA) and is a co-polymer of PHB and PHV organism used: alcaligenes eutrophus Development: through the fermentation of sugars by the bacterium. Properties: biodegradable and biocompatible Uses: disposable containers, stitches, disposable razors, rubbish bags |
|
|
Properties of alkanols |
Mp and bp high as hydrogen bonding exists smaller alkanols are soluble and fully miscible Solvents - able to dissolve polar and non-polar solutes (polarity and dispersion forces with non-polar) inflammable - used as a fuel |
|
|
Conditions for fermentation |
- suitable microorganism (yeast) - water - suitable temp 30-40 Low oxygen concentrations a small amount of yeast nutrients
|
|
|
Process of industrial production of ethanol from sugar cane |
Sugar-cane harvested and grinded Hydrolyse with acids at 100 degrees to break bonds forming glucose Filter to separate the reaming solid residue of cellulose and lignin The solid residue is further hydrolysed with stronger acids Add calcium hydroxide to sugar solution to neutralise filter the sugar solution to remove residue Oxygen-free tank, warmed to 37 degrees, fermented using yeast to produce ethanol and carbon dioxide Distilled |
|
|
Problems encountered with fermentation of sugar experiment |
Escaping of CO2 to atmosphere - lime water solution to catch carbon dioxide, side-arm flask
|
|
|
Use of ethanol as a fuel |
Able to undergo combustion, liquid - transportable, renewable
|
|
|
Advantages of ethanol as a fuel |
Energy-dense fuel when burnt plant material needed which are renewable Carbon neutral Can be mixed with lower-octane petrol Produces less polluting emissions as it combusts more completely Ethanol-air mixtures more readily ignite |
|
|
Disadvantages of ethanol as a fuel |
- More energy needed to produce the ethanol is substantial. - Twice the amount of farmland - Alteration of motor engines - more expensive than petrol
|
|
|
Molar heat of combustion |
Heat energy released when one ole of a substance undergoes complete combustion with oxygen at SLC pressure, with the final products being CO2 |
|
|
Oxidation State |
Another name for the valency of an element |
|
|
A galvanic cell |
electricity produced from a redox reaction. Flow of electrons. Redox reactions are electron-transfer reactions |
|
|
ANODE |
more reactive substance oxidised. the anode is being oxidised ANOX (+) |
|
|
CATHODE |
the cathode (-) is being reduced red cat |
|
|
Elecrrode |
anything through which electrical current passes --> metal conductors placed in the electrolytes |
|
|
Electrolyte |
Is any solution that can conduct electricity; all salt solution |
|
|
Purpose of salt bridge |
KNO3 - completes the circuit, maintains electrical neutrality - thus the positive charge builds up, negative nitrate ions migrate towards that cell to neutralise the charge, hence it allows ions to flow |
|
|
The total voltage of a galvanic cell |
EMF (electromotive force) - each electrode/electrolyte has a fixed voltage known as the standard reduction potential (E*) |
|
|
The dry Cell (Leclanche Cell) - structure |
Structure: zinc outer casting; negative electrode, aqueous paste of ammonium chloride and a mixture of powdered carbon, manganese dioxide and ammonium chloride around a carbon rod (positive terminal) |
|
|
The dry cell - chemistry |
Zn|Zn2+||Mn4+|Mn3+ |
|
|
The dry cell - cost and practicality |
relatively cheap, practical to manufacture, light and portable, short shelf-life |
|
|
The dry cell- impact on society |
first commercially produced batter, made portable devices possible, widely used as it is cheap and portable |
|
|
The dry cell - environmental impact |
- very minimal, the manganese (III) product is readily oxidised to manganese (IV) which is stable, the ammonium salts and carbon are also harmless. |
|
|
The Silver oxide (button cell) - structure |
Made of layers of chemcials within a steel case. Powdered silver (I) oxide (cathode). Top is powdered zinc (anode) separated by a paste of alkaline potassium hydroxide |
|
|
The silver oxide (button cell) - chemistry |
Zn|Zn2+||Ag+|Ag |
|
|
The silver oxide (button cell) - cost and practicality |
- very expensive in comparison, provides large amount of electricity with very constant voltage for long periods of time, non-rechargable |
|
|
The silver oxide (button cell) - impact on society |
High constant voltage allows it to have man applications to last for years - watches, calculators, digital cameras |
|
|
The silver oxide (button cell) - environmental impact |
- minimal, all stable, insoluble and non-toxic compounds, potassium hydroxide is strongly alkaline; however is in quite dilute form as an electrolyte |
|
|
Isotopes |
Atoms with the same chemistry however their mass numbers are different |
|
|
Radioactivity |
Spontaneous emission of radiation from radioactive isotopes in which their atoms are unstable |
|
|
Conditions to predict radioactivity |
- proton-neutron ratio: 1:1 (z<20) 1: 1.3 (Z=30) - atomic number > 83 |
|
|
How are transuranic elements produced |
Man-made elements above 92 - neutron bombardment in nuclear reaction - fission chain-reaction produces large amounts of neutrons. - Fusion reactions (in particle accelerators) - larger elements z>95. Achieved by colliding heavy nuceli together |
|
|
Recent discoveries of elements |
Livermanium: element 116. Russia produced by the fusion of curium-248 and calcium-48 Ununpentium: element 115 2004, Joint Institue for Nuclear Reasearch (Russion0 and Larence Livermore National Laboratory (America) - fusion of americium-243 and calcium-48 Ununtrium: element 113 2004 through the alpha decay of ununpentium |
|
|
Cobalt-60: |
Produced by the neutron bombardment of cobalt-59 gamma rays are very penetrative and destructive to living cells Used to sterilise medical supplies, see inside plane welds, beams focused into the tumour, half-life of 5.3 years. Disadvantages: healthy cells also killed, staff using equipment must be protected |
|
|
Amercium-241 |
domestically used in smoke alarms Produced by the neutron bombardment of plutonium-241.
|
|
|
Caesium-137 |
- beta and gamma emitter - the irradiation of food materials, thickness gauges and radiography of machinery and welds, 30 year half-life (30 yrs), lower energy emission, sufficient gamma rays to destroy bacteria, Disadvantages: destroys some of the vitamin content, may lead to the formation of harmful compounds in food |
|
|
Benefits of radioisotopes - medicine |
non-invasive diagnostic procedures (heart, brain, kidney, thyroid), introduction of radiation therapy for treating cancer |
|
|
Benefits of radioisotopes - industry |
- ability to make monitoring equipment more sensitive, precise and reliable, do things more efficiently and reliably, do things that were otherwise impossible (examine buildings and machinery for weld and structural faults) |
