chem - separate chem II (9)

• Metals are shiny, good heat and electrical conductors, hard, and tough.
• Metals are used in cars, bridges, and electrical cables.
• The flame colour for each ion is: Lithium ion, Li+ (red), Sodium ion, Na+ (yellow), Potassium ion, K+ (lilac), Calcium ion, Ca2+ (orangey red), Copper ion, Cu2+ (bluey green).
• Using sodium hydroxide solution, Aluminium ion, Al3+ results in a white precipitate that dissolves when excess NaOH is added, Calcium ion, Ca2+ results in a white precipitate, Copper ion, Cu2+ results in a blue precipitate, Iron (II) ion, Fe2+ results in a green precipitate, Iron (III) ion, Fe3+ results in a brown precipitate, Ammonium ion, NH4+ results in a pungent-smelling gas being produced.
• Chemical test for ammonia involves making damp red litmus paper turn blue and forming a white smoke of ammonium chloride when hydrogen chloride gas is held near it.
• Carbonate ion, CO32- can be identified using dilute acid and identifying the CO2 evolved, where gas produced bubbled through limewater, if the limewater goes cloudy, the gas is CO2.
• Sulphate ion, SO42- can be identified using dilute hydrochloric acid and barium chloride solution, where a white precipitate will form.
• Chloride ion, Cl, bromide ion, Br- , iodide ion, I- can be identified using dilute nitric acid and silver nitrate solution, where a white precipitate is produced for chloride, cream for bromide, yellow for iodine.
• Elements and compounds can be detected and identified using instrumental methods, which are accurate, sensitive and rapid such as gas chromatography and mass spectrometry.
• Data from a flame photometer can be used to identify metal ions in a sample and determine the concentration of metal ions in dilute solutions.
• In the flame photometer, the coloured light from a vaporised sample can be split to produce an emission spectrum, each metal ion produces a unique emission spectrum.
• Problems associated with polymers include availability of starting materials, landfills, and recycling.
• Investigate the temperature rise produced in a known mass of water by the combustion of alcohols.
• A polymer is a very long chain molecule made of many small molecules called monomers.
• Alcohols contain the functional group –OH.
• The temperature is raised more as the chain length of the alcohols increases, because the combustion of longer chain alcohols releases more energy.
• During combustion, the carbon and hydrogen in the fuels are oxidised to produce carbon dioxide and water.
• The first 4 members of the series of alcohols are methanol, ethanol, propanol and butanol.
• Differentiation with bromine water involves alkenes reacting with bromine water, resulting in a change from orange to clear, while alkanes do not react.
• DNA is a polymer made from 4 different monomers called nucleotides, starch is a polymer based on sugars, and proteins are polymers based on amino acids.
• Any alkene can be used as a monomer to create a polymer due to the c=c bond.
• Ethanoic acid is a member of the carboxylic acids, they have the functional group –COOH.
• Alkenes can be used to make polymers such as polyethene and polypropene by addition polymerisation.
• The first four members of the series of carboxylic acids are methanoic acid, ethanoic acid, propanoic acid and butanoic acid.
• A monomer is the same as the repeat unit, just replace c-c with c=c and remove brackets + "n".
• Polymers have various uses and their properties include being flexible, cheap, electrical insulators, flexible and strong, tough, cheap, durable, and tough, cheap, and durable.
• The metal present in a sample is identified by comparing its spectrum with reference spectra, these are emission spectra from known metal ions.
• If two match, they are from the same metal ion.
• As the side of cube decreases by a factor of 10, the surface area to volume ratio increases by a factor of 10.
• Members of a given homologous series have similar reactions because their molecules contain the same functional group and use this to predict the products of other members of these series.
• Ethanol is produced by fermentation with yeast, using renewable sources, and is produced from carbs.
• Nanoparticles can be used to produce highly selective sensors.
• Nanoparticles involve fullerenes.
• Nanoparticles are 1-100 nanometres across and contain a few hundred atoms.
• Nanotubes could make stronger, lighter building materials.
• The effects of nanoparticulate materials are unknown and this is worrying for some people as risks are not fully known.
• Ethanol can be oxidised to form ethanoic acid.
• Nanoparticles are smaller than fine particles, which have diameters between 100 and 2500 nm.
• Some nanoparticulate materials may be harmful to health as they may enter the bloodstream and cause harm.
• A nanoparticle has different properties to the 'bulk' chemical it's made from, because of their high surface area to volume ratio.