Tests Flashcards
Method for flame tests
Dip clean platinum loop wire in HCl and then hold it in the flame. Dip into substance and then hold in flame
Flame test for calcium
Orange - Red flame
Flame test for lithium
Red flame
Flame test for potassium
Burns with lilac flame
Copper flame test
Blue- green flame
Insoluble coloured precipitate method
Add sodium hydroxide NaOH to the mystery solution and see if a coloured insoluble hydroxide is formed
If copper (II) hydroxide is formed
Blue precipitate
If iron (II) hydroxide is formed
Green precipitate
If iron (III) hydroxide is formed
Reddish brown precipitate
Ammonium compound + NaOH
Gives off ammonia
The test for ammonia gas is damp red litmus paper will turn blue
Test for carbonates
Add dilute HCl to sample
CO2 released if carbonate present
Carbonate + acid—> carbon dioxide + water
Test for sulfates
Add dilute HCl followed by Barium chloride and if sulfates are present it produces a white precipitate
Barium ions + sulfate ions —> barium sulfate
Test for halides
Add dilute nitric acid followed by silver nitrate solution
Chloride- white precipitate of silver chloride
Bromide - cream precipitate of silver bromide
Iodide - yellow precipitate of silver iodide
Test for chlorine gas
Chlorine gas bleached damp blue litmus paper
Test for oxygen gas
Relights a glowing splint
Test for carbon dioxide gas
Turns limewater cloudy
Test for hydrogen gas
Hydrogen makes a squeaky pop with lit splint
Ammonia gas test
Turns damp red litmus paper blue
Wet copper sulfate colour
Blue
Dry copper sulfate colour
White
