G) Chemical tests

how to test for hydrogen

squeaky pop with lit splint

how to test for oxygen

relights a glowing splint

how to test for carbon dioxide

bubble through limewater

colourless —> cloudy

how to test for ammonia

add sodium hydroxide

will turn moist litmus paper from red to blue, and moist universal indicator paper to blue

how to test for chlorine gas

damp blue litmus paper will turn to red and then to white

flame test for Lithium

Li⁺

red

flame test for Sodium

Na⁺

yellow

test for potassium

K⁺

flame = lilac

test for calcium ions

Ca²⁺

flame test = orange-red

test for copper

Cu²⁺

flame test = blue-green

how to test for iron (II)

Fe²⁺

add sodium hydroxide = green precipitate

how to test for iron (III) ions

Add sodium hydroxide = brown precipitate

how to test for copper (II) (using NaOH)

Cu²⁺

add sodium hydroxide = blue precipitate

test for ammonium

NH₄⁺

add sodium hydroxide solution

Gas → red litmus blue

how to test for sulfate ions

add HCl to remove any impurities

add BaCl₂ solution → if present, a white precipitate will form

how to test for carbonate ions

add hydrochloric acid , if carbonate ions are present, fizzing will occur

carbon dioxide is evolved (test using limewater)

how to test for chloride ions

add nitric acid to remove any impurities

add silver nitrate, if chloride ions are present they will produce a white precipitate

how to test for bromide ions

add nitric acid to remove any impurities

add silver nitrate, if present they will produce a cream precipitate

how to test for iodide ions

add nitric acid to remove any impurities

add silver nitrate solution, if iodide ions are present they will produce a yellow precipitate