tests Flashcards
flame test?
nichrome wire dipped in HCl then the solid crushed into a powder.
flame test colours?
lithium= red sodium= yellow potassium= lilac calcium= brick red barium= apple green copper= green
iron (II) and hydroxide ions test for metal ions
green gelatinous precipitate
iron (III) and hydroxide ions?
orange gelatinous precipitate
copper (II) and hydroxide ions?
pale blue gelatinous precipitate
lead (II) and iodide ions?
bright yellow precipitate
ammonium ions and hydroxide ions?
ammonia gas given off and smells. makes damp red litmus paper go blue
silver nitrate and chlorine?
white precipitate
silver nitrate and bromine?
cream precipitate
silver nitrate and iodine?
pale yellow precipitate
silver and hydroxide ions?
brown gelatinous precipitate
calcium and hydroxide ions?
white gelatinous precipitate
zinc (II) and hydroxide ions?
white then slowly colourless
aluminium (III) and hydroxide ions?
white then colourless
HCl and carbonates?
will fizz to give off carbon dioxide.
carbon dioxide test?
will turn limewater cloudy
to identify a sulphate ion what do you do?
add HCl and barium chloride. white precipitate means a sulphate was originally made because the precipitate is barium sulphate.
a test for hydroxide ions?
damp red litmus paper turns blue indicating an alkali
how do you test for a nitrate?
warm with NaOH and aluminium foil. Al reduces nitrate ions to NH4+ ions. ammonium then reactis with NaOH to make NH3 and water. if ammonia is given off, then it smells and makes damp red litmus paper blue
nitrate (V) react with Al to make an alkali giving off what?
- add NaOH, aluminium foil, or devardas alloy
- Al reduces nitrate ions to produce ammonia gas
- smells and damp red litmus goes blue
how can you visualise TLC stuff
iodine
florescence
what is an indicator for a.a?
ninhydrin
how can you tell that you have oxidised a primary alcohol?
the dichromate ions goes from orange to green to leave you with Cr(3+)
test for an alkene?
add bromine water or bromine, will go from orange to colourless
what is the Fehlings test?
- fehlings and sample
- water bath
- aldehyde = brick red precipitate
ketone = nothing happens
the red precipitate is copper (I) from the reduction of copper (II). the extra electron comes from the oxidation of the aldehyde to a carboxylate ion
what is the tollens test?
- silver nitrate and NaOH make a brown precipitate
- add dilute ammonia solution until brown completely goes
- water bath
- add sample
- aldehyde = silver mirror
- ketone = nada
diamminesilver ions reduced with electron comes from oxidation aldehyde to carboxylate ion. produces ammonia and silver
