qa

Fe2⁺

green ppt ins in xs

Fe3⁺

reddish brown ppt ins in xs

Cu2⁺

blue ppt ins in xs
blue ppt sol in xs to form dark blue solution

Al3⁺

white ppt sol in xs
white ppt ins in xs

Ca2⁺

white ppt ins in xs
no ppt

Zn2⁺

white ppt sol in xs

NH4⁺

no ppt, ammonia produced upon warming

CO₃^-

add dilute acid, bubble gas into limewater
effervescence, carbon dioxide gas produced

NO₃^-

add aq sodium hydroxide, add aluminium foil, warm mixture
effervescence, ammonia gas produced

SO₄^2-

add nitric acid, add aq barium nitrate
white ppt (barium sulfate)

Cl-

add dilute nitric acid, add silver nitrate

white ppt (silver chloride)

H₂

place burning splint on the mouth of test tube

burning splint extinguished with a “pop” sound

O₂

insert glowing splint into the test tube

glowing splint rekindled

CO₂

bubble gas into limewater

white ppt formed

Cl₂

place damp blue litmus paper at the mouth of test tube

blue turn red then bleached

SO₂

place filter paper soaked with KMnO₄ at mouth of test tube
KMnO₄ turn colourless

NH₃

place damp red litmus paper at the mouth of test tube

litmus paper blue