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Separate chemistry 2

Edexcel GCSE ChemistryTopic 9 of 939 lessons

Revision notes for Separate chemistry 2 in Edexcel Chemistry (1CH0). Every lesson in BrainCake comes with R.E.C.I.P.E. recall steps, a quick check and spaced reviews.

  1. Identifying the ions in an unknown saltTo identify an unknown salt you test for its positive ions (cations) and its negative ions (anions) separately, then combine the results.
  2. Energy released by burning alcoholsIn this practical you compare how much energy the alcohols ethanol, propanol, butanol and pentanol release when they burn.
  3. Why the test for an ion must be uniqueA test for an ion is unique if only that one ion gives the result.
  4. Flame tests for metal ionsA flame test identifies some metal ions in a solid by the colour they give a flame.
  5. Testing for metal ions with sodium hydroxideMany metal ions make insoluble metal hydroxides when sodium hydroxide solution is added.
  6. The chemical test for ammoniaAmmonia, NH3, is a colourless gas with a sharp smell.
  7. Testing for carbonate ionsA carbonate such as calcium carbonate, CaCO3, reacts with any dilute acid to make a salt, water and carbon dioxide.
  8. Identifying the ions in an unknown saltAn unknown salt contains a positive ion (a cation) and a negative ion (an anion).
  9. Instrumental methods of analysisSimple chemical tests rely on a person seeing a colour change, a precipitate or fizzing.
  10. Using data from a flame photometerA flame photometer is an instrument that gives a measured reading for the metal ions in a dilute solution.
  11. Formulae and structures of the first four alkanesAlkanes are compounds made of carbon and hydrogen only, so they are hydrocarbons.
  12. Why alkanes are saturated hydrocarbonsA hydrocarbon is a compound made only of carbon and hydrogen atoms.
  13. Formulae and structures of the alkenesThe alkenes are a family of hydrocarbons, which means they contain only carbon and hydrogen.
  14. Alkenes as unsaturated hydrocarbonsA hydrocarbon is saturated if all the bonds between its carbon atoms are single bonds.
  15. Addition reaction of alkenes with bromineAlkenes take part in addition reactions, in which two molecules join to make a single product and nothing else is formed.
  16. Bromine water test for alkenesBromine water is an orange solution of bromine in water.
  17. Complete combustion of alkanes and alkenesAlkanes and alkenes burn in air.
  18. PolymersA polymer is a substance made of very long molecules.
  19. Poly(ethene) from etheneEthene, C2H4, is a small molecule with a C=C double bond.
  20. Other addition polymersOther addition polymers are made in the same way as poly(ethene).
  21. Monomers and repeating unitsAn addition polymer is drawn as its repeating unit in brackets with a small n after them.
  22. Properties and uses of polymersThe use of a polymer depends on its properties, and the properties depend on the atoms in its repeating unit.
  23. Polyesters and condensation polymerisationPolyesters are not made from alkenes.
  24. Problems with polymersPolymers are very useful, but they cause problems.
  25. Recycling polymersMost polymers are made from crude oil, which is a limited resource that cannot be replaced.
  26. Natural polymersA polymer is a very long molecule made from many small units called monomers joined together in a chain.
  27. AlcoholsAlcohols are a family of compounds that contain carbon, hydrogen and oxygen.
  28. The alcohol functional group and dehydrationA functional group is the atom or group of atoms that gives a family of compounds its typical reactions.
  29. Carboxylic acidsCarboxylic acids are another family of compounds made of carbon, hydrogen and oxygen.
  30. Properties of carboxylic acidsThe functional group in carboxylic acids is -COOH.
  31. Oxidation of ethanol and other alcoholsAlcohols can be oxidised, which means they gain oxygen.
  32. Homologous series and similar reactionsA homologous series is a family of compounds whose molecules have the same functional group.
  33. Making ethanol by fermentationFermentation is used to make ethanol from carbohydrates such as sugar or glucose.
  34. Concentrating ethanol by fractional distillationFermentation only makes a dilute solution of ethanol in water, up to about 15 percent ethanol, because stronger solutions kill the yeast.
  35. The size of nanoparticlesSizes at this level are measured in nanometres.
  36. Properties and uses of nanoparticlesThe main reason nanoparticles behave differently from the same material in bulk is their very large surface area to volume ratio.
  37. Risks of nanoparticulate materialsNanoparticles are structures between 1 and 100 nanometres across, and they are now used in sunscreens, cosmetics, sports equipment, fabrics and…
  38. Comparing glass, ceramics, polymers, composites and metalsTo compare materials using data, look at the same property for each material, such as density, melting point or strength, and say which is higher or…
  39. Choosing materials for a useA material is chosen because its properties match what the job needs.

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