inorganic tests

test for hydrogen

use a burning splint held at the open of a test tube of the gas —> „squeaky pop“ sound

test for oxygen

use a glowing splint, insert into a test tube of the gas —> splint relights

test for CO2

bubble gas through limewater (Ca(OH)2) —> turns milky(cloudy)

test for ammonia

- makes damp red litmus paper turn blue

- forms a white smoke of NH3Cl when HCl (conc) is held near it

test for chlorine

damp litmus paper is bleached and turns white

test for water

add anhydrous CuSO4 —> color change from white to blue

test for purity of water

- measure the boiling point —> 100°C if pure

- freezing/melting point —> 0°C if pure

procedure flame test

- dip at Pt or nichrome wire into HCl (aq) (conc) to clean it

- dip into the chloride of the metal / the salt that needs to be tested

- hold the end of the wire within a non-luminous Bunsen flame to observe the color

lithium flame color

red

sodium flame color

yellow

potassium flame color

lilac

calcium flame color

orange-red

copper flame color

blue-green

strontium flame color

crimson red

test for ammonium

add a small amount of NaOH —> ammonia gas produced turns damp litmus paper blue

test for copper (III)

add a small amount of NaOH —> light blue precipitate formed

barium flame color

apple green

test for iron (II)

add a small amount of NaOH —> green precipitate is formed

test for iron (III)

add a small amount of NaOH —> red-brown precipitate is formed