Chemical testing Flashcards
(16 cards)
How do you test for calcium ions
Add sodium hydroxide
Ca2+ + 2OH- –> Ca(OH)2
Forms a white precipitate
How to test for magnesium ions
Add sodium hydroxide
Mg2+ + 2OH- –> Mg(OH)2
Forms a white precipitate
How to test for aluminium ions
Add sodium hydroxide
Al3+ + 3OH- –> Al(OH)3
White precipitate that dissolves in excess
How to test for copper ions
Add sodium hydroxide
Cu2+ + 2OH- –> Cu(OH)2
Blue precipitate
How to test for iron (II) ions
Add sodium hydroxide
Fe2+ + 2OH- –> Fe(OH)2
Green precipitate
How to test for iron (III) ions
Add sodium hydroxide
Fe3+ + 3(OH)- –> Fe(OH)3
brown precipitate
What colour is sodium in a flame
Yellow
What colour is lithium in a flame
Crimson
What colour is potassium in a flame
Lilac
What colour is calcium in a flame
Orange red
What colour is copper in a flame
Green
How to identify carbonates
Use limewater test
How to identify halide ions
Add nitric acid and silver nitrate, colour of precipitate determines the ion
Which halide ion forms which colour precipitate in testing
Chloride - white
Bromide - cream
Iodide - yellow
How to identify sulfate ions
Add hydrochloric acid then barium chloride. This should form a white precipitate
