Quantitative Analysis Flashcards
what are the different cations to be tested?
- ammonium
- zinc
- calcium
- lead (II)
- copper (II)
- iron (II)
- iron (III)
what happens when ammonium reacts with aqueous sodium hydroxide?
no precipitate, colourless and pungent gas is given off (ammonia)
what happens when ammonium reacts with aqueous ammonia
-
what happens when zinc reacts with aqueous sodium hydroxide?
white precipitate soluble in excess sodium hydroxide forming a colourless solution
what happens when zinc reacts with aqueous ammonia?
white precipitate soluble in excess aqueous ammonia forming a colourless solution
what happens when calcium reacts with aqueous sodium hydroxide?
white precipitate insoluble in excess sodium hydroxide
what happens when calcium reacts with aqueous ammonia?
no visible reaction
what happens when lead (II) reacts with aqueous sodium hydroxide?
white precipitate soluble in excess sodium hydroxide forming a colourless solution
what happens when lead (II) reacts with aqueous ammonia?
white precipitate insoluble in excess aqueous ammonia
what happens when copper (II) reacts with aqueous sodium hydroxide?
blue precipitate insoluble in excess sodium hydroxide
what happens when copper (II) reacts with aqueous ammonia?
blue precipitate soluble in excess aqueous ammonia forming a deep blue solution
what happens when iron (II) reacts with aqueous sodium hydroxide?
dirty green precipitate insoluble in excess sodium hydroxide
what happens when iron (II) reacts with aqueous sodium ammonia?
dirty green precipitate insoluble in excess aqueous ammonia
what happens when iron (III) reacts with aqueous sodium hydroxide?
reddish brown precipitate insoluble in excess sodium hydroxide
what happens when iron (III) reacts with aqueous ammonia?
reddish brown precipitate insoluble in excess aqueous ammonia
what are the different anions to be tested?
- sulfate
- chloride
- nitrate
- carbonate
how to test for sulfate?
add dilute nitric acid followed by aqueous barium nitrate into test tube
what is observed in sulfate test?
no visible reaction on adding dilute nitric acid. white precipitate formed on adding barium nitrate
how to test for chloride?
add dilute nitric acid followed by aqueous silver nitrate into test tube
what is observed in chloride test?
no visible reaction on adding dilute nitric acid. white precipitate formed on adding silver nitrate
how to test for nitrate?
add aqueous sodium hydroxide and add aluminium foil into the test tube. warm gently and test gas with moist red litmus paper
what is observed in nitrate test?
effervescence observed. colourless and pungent gas is given off which turns moist red litmus paper blue (ammonia)
how to test for carbonate?
add dilute hydrochloric acid and bubble the gas evolved into aqueous calcium hydroxide (limewater)
what is observed in carbonate test?
effervescence observed. colourless and odourless gas is given off which forms a white precipitate in calcium hydroxide (carbon dioxide)
what are the different gases to be tested?
- ammonia
- carbon dioxide
- chlorine
- hydrogen
- oxygen
- sulfur dioxide
how to test for ammonia?
place damp red litmus paper above the mouth of the test tube
what is observed in ammonia test?
colourless and pungent gas produced which turns moist red litmus paper blue
how to test for carbon dioxide?
bubble gas through aqueous calcium hydroxide (limewater)
what is observed in carbon dioxide test?
white precipitate is formed
how to test for chlorine?
place damp blue litmus paper at the mouth of the test tube
what is observed in chlorine test?
damp blue litmus paper turns red and is then bleached
how to test for hydrogen?
insert a lighted splint into the test tube
what is observed in hydrogen test?
lighted splint extinguishes with a ‘pop’ sound
how to test for oxygen?
insert a glowing splint into the test tube
what is observed in oxygen test?
glowing splint will relight/burst into flames
what is one way to test for sulfur dioxide?
place a filter paper strip soaked with acidified potassium manganate (VII) above the mouth of the test tube
what is the observation of the first sulfur dioxide test?
the purple acidified potassium manganate (VII) decolourises
what is a another test for sulfur dioxide?
place a filter paper soaked with acidified potassium dichromate (VI) above the mouth of the test tube
what is observed in the second sulfur dioxide test?
the acidified potassium dichromate (VI) turns from orange to green
