IGCSE Chemistry Revision

1. Fume cuboard
2. Well ventilated room
   1. Prevents burning of a substance
3. e.g. Nitrogen Dioxide, Ammonia, Bromine

1. Add anhydrous Copper(II) Sulphate (white to blue)
2. Add anhydrous Cobalt(II) Chloride (blue to pink)

1. Alkenes: Add (if liquid) or pass through (if gas) bromine water and shake (brown to colourless)
2. Alkanes: (remain orange/brown)

1. Test melting/boiling point and compare to correct value

Attachments:

• Chemistry ATP Tests

1. Add silver nitrate (white ppt. formed)

1. Gases less dense than air
2. e.g. Hydrogen, Ammonia

1. Gases more dense than air
2. e.g. Carbon Dioxide

1. Insoluble gases
2. e.g. Methane

1. Heat till point of crystallisation, allow to cool slowly, filter and dry
   1. Place a stirring rod in solution and if crystals form on it, it's the point of crystallisation
2. Crystallisation is the formation of solid crystals of a substance by precipitating it out from a staurated solution

1. Glucose and yeast used (yeast contains enzymes)
   1. 37 degrees is optimum for enzymes
   2. Reaction might stop due to an excess in conc. of alcohol, the yeast dies or Glucose finishes up
2. Bung is used to let Carbon Dioxide out and prevent entry of Oxygen
   1. Oxygen would oxidise the alcohol to Carboxylic Acid and affect anaerobic respiration

1. Spray locating agent if colourless dye (such as amino acids and sugars)
   1. RF = distance moved by dye/distance moved by solvent

1. Concentration promotes the discharge of ions further down the reactivity series because their compounds are stable
2. Suitable electrodes: Graphite/Carbon/Steel

1. Acidified Potassium Manganate(VII) (purple to colourless)
2. Acidified Potassium Dichromate(VI) (orange to green)

1. All metals (mention Group 1 when asked)
2. Aqueous Potassium Iodide (colourless to brown)
3. Sulphur Dioxide

1. Concentrated Sulphuric Acid (all gases except Ammonia)
2. Calcium Oxide (for Ammonia and neutral gases)
3. Anhydrous Calcium Chloride (all gases except Ammonia)

1. Ninhydrin

1. To liquify vapour in distillation and returning unreacted vapour back to the solution

1. To cool the gases in fractional distillation by absorbing heat from them

1. To separate various liquids using their boiling points

1. In pipettes to prevent liquid from entering mouth

1. Zinc is a grey solid (white compounds)
2. Lead is a shiny bluish metal
3. Iron is a shiny blackish solid
   1. Iron (II) salts are grey-green. Iron (III) salts are reddish-brown.
4. Group 1, 2 metals are white/silvery white
5. Group 3 metals are shiny grey
6. Copper is a pinkish solid
   1. Copper(II) sulphate/hydroxide/nitrate are blue. Copper(II) chloride/carbonate are green.

1. Iodine is a black solid
   1. Its vapours are purple. Silver iodide and Lead iodide are yellow.
2. Chlorine is a green gas
   1. Silver chloride and Lead chloride are white
3. Bromine is a red-brown gas
   1. Silver bromide and Lead bromide are cream
4. Nitrogen dioxide is a brown gas.
5. Sulphur and Phosphorus are yellow solids