Chemical tests

Test for hydrogen

Put a lit splint into a test tube if there is a pop sound there is hydrogen

Test for Oxygen

Put a glowing splint in a test tube if it relights there is oxygen

Test for carbon dioxide

Blow into a test tube that has lime water if the lime water turns cloudy there is carbon dioxide

Test for ammonia

Damp red litmus paper turns blue

Test for chlorine

Chlorine bleaches damp blue litmus paper, turning it white

Flame test

• Dip a piece of nichrome wire into the hydrochloric acid

• Heat the wire in the Bunsen burner until the flame burns without colour

• Dip the wire back into the acid, then into the sample you want to test

• Hold the wire in the flame and observe the flame colour

Metal ions flame colour

• Lithium- red flame

• Sodium-yellow flame

• Calcium- orange-red flame

• Potassium-lilac flame

• Copper- blue-green flame

Test for Cations

Add a few drops of sodium hydroxide solution to your compound

Cu²⁺→ blue precipitate

Fe²⁺→ green precipitate

Fe³⁺→ brown precipitate

Test for Ammonium ions

Add small amount of ammonium chloride to a test tube and add sodium hydroxide as well and warm it over a Bunsen burner. Place a red litmus paper in the test tube and see the colour change, if ammonia is given off there is ammonium ions.

Test for anions

Add dilute nitric acid followed by silver nitrate solution to the sample

Cl^-→ white precipitate

I^-→ yellow precipitate

Br^-→ cream precipitate

Test for presence of water using anhydrous copper sulfate and test the purity of water

Add anhydrous copper sulfate to the sample if the white powder turns blue there is water.

If the water boils at 100^oC and freezes at 0^oC it is pure