chemical analysis Flashcards
what is the test and result for hydrogen
light a burning splint and place it in a test tube full of hydrogen
squeaky pop
what is the test and result for oxygen
place a glowing splint in a test tube full of oxygen
it will relight
what is the test for carbon dioxide
bubble gas through limewater
turns cloudy
what’s the test and result for chlorine
damp litmus paper at the end of a test tube
will bleach the litmus paper white
what are anions
negatively charged ions
what is the test and result for carbonate ions (anion)
add dilute HCL into carbonate solution
take any gas that’s produced and bubble through limewater to see if it’s carbon dioxide
result - cloudy
what is the test for sulfate ion(anion)
add dilute HCL to get rid of impurities
add BARIUM CHLORIDE
should form white precipitate
what is the test and result for all 3 halide ions
Chloride- Add dilute nitric acid and add silver nitrate
result - white precipitate
Bromide- Add dilute nitric acid and add silver nitrate
result- Cream precipitate
Iodide- same
result - Yellow precipitate
what are the flame tests results
Lithium - Crimson red
Sodium- yellow flame
Potassium - lilac
copper is green flame
calcium produces orange- red flame
what is one disadvantage of flame tests
it may be difficult to distinguish and the flame colours of some ions may be hidden by the colours of others
what is flame emission spectroscopy
when a sample of the metal ion in a soloution is put into a flame and the light given out is passed through a spectroscope to produce a line spectrum
what are the advantages of instrumental methods
rapid
accurate
sensitive ( will work on a tiny sample of the metal compound )
what are cations
positive ions
what is the test for all metal hydroxides (cations)
calcium - add sodium hydroxide
white precipitate
Magnesium- add sodium hydroxide
white precipitate
aluminium- add sodium hydroxide
White precipitate BUT DISSOLVES IN EXCESS SODIUM HYDROXIDE
Copper (II) add sodium hydroxide
blue precipitate
Iron (II) - add sodium hydroxide
produces green precipitate
iron (III) add sodium hydroxide
produces brown precipitate
