chemical tests Flashcards
what are the cation tests
flame, NaOH, NH3, NH4 +
what are the anion test
halide, SO4, SO3, CO3, NO3
flame test
clean wire with concentrated HCl
dip wire in acid and then in compound
place compound in blue bunsen burner flame
flame color:
Cu
K
Li
Na
Ca
Ba
Mg
blue/green
lilac
bright red
orange/yellow
brick red
apple green
colourless
NaOH/ NH3 test
dissolve sample in water
add drops of NaOH/NH3
observe colour of precipitate
add excess NaOH/NH3
observe colour of precipitate
group 1 NaOH/NH3 test
all colourless
group 2 NaOH/NH3 test
all white solid
Fe 2+ NaOH/NH3 test
all green turns orange solid
Fe 3+ NaOH/NH3 test
all orange/brown
Cu 2+ NaOH/NH3 test
NaOH- blue solid
blue aq
NH3- dark blue solid
dark blue aq
Cr 3+ NaOH/NH3 test
all green/gray solid
Zn 2+ NaOH/NH3 test
NaOH- white solid
colourless aq
NH3- white solid
colourless aq
Al 3+ NaOH/NH3 test
NaOH- white solid
colourless aq
NH3- white solid
white solid
SO4 test
add acid (HCL/ HNO3)
add Ba(NO3)2 or BaCl2
if SO4 present white ppt is formed
SO3 test
add any acid
test gas with K2Cr2O7 or KMnO4
K2Cr2O7- orange to green
KMnO4- purple to faint pink