Chemical Analysis Flashcards
How to test for ammonia
hold damp red litmus paper over heated test tube (with ammonium solution inside), if the litmus turns blue you have ammonia
How to test for Carbon Dioxide
bubble gas through limewater, if its carbon dioxide water will turn cloudy white
How to test for chlorine?
Hold damp blue litmus paper of test tube with gas, if gas is chlorine it will turn red and then blue
How to test for Hydrogen?
Put a burning splint in test tube and a squeaky pop should be heard
How to test for Oxygen?
Put glowing splint in test tube, if gas is oxygen it should relight
What must you do before every flame test?
Dip nichrome wire in dilute acid to prevent contamination
What colour does lithium turn?
Red
What colour does Sodium turn?
yellow
What colour does Potassium turn?
lilac
What colour does Calcium turn?
orange-red
What colour does Copper turn?
Blue-green
What must you add to test for cations?
NaOH (sodium hydroxide)
When NaOH added what precipitate is formed for Copper 2+?
Light blue
When NaOH added what precipitate is formed for Iron 2+?
green
When NaOH added what precipitate is formed for Iron 3+?
Brown
When NaOH added what is formed for Ammonium?
Ammonia Gas is formed
What is the test for carbonate ion?
A bubble gas through limewater, should turn cloudy white, white precipitate formed
What is the test for Halide ion?
Add nitric acid, add silver nitrate, silver halide precipitate forms. Chloride - white, Bromide - cream, Iodide - Yellow
What is the test for Sulphate Ions?
Add hydrochloric acid, add barium chloride, white precipitate should form
How to test for water?
Chemical: Anhydrous copper(II) sulphate turns from white to blue
Physical: Check boiling point, should be 100˚C
