Analytical Chemistry Flashcards
Describe the test for carbonates
Add any acid to the solution/substance
Bubble the gas produced through limewater
If it goes cloudy it is a carbonate
Describe the text for sulphates
Add hydrochloride or nitric acid to the substance
Add barium chloride
If there is a white precipitate it is a sulphate
Describe the test for halides
Add sulphuric or nitric acid to the substance Add silver nitrate If precipitate: Chloride: white Bromide: cream Iodide: yellow
Describe the test for ammonium
Add sodium hydroxide to the substance (to form ammonia)
Heat gently to release the ammonia from solution
Hold damp red litmus over the mouth of the test tube
If it turns blue it is ammonium
What colour precipitate will be created when sodium hydroxide is added to Fe2+
Green
What colour precipitate will be created when sodium hydroxide is added to Fe 3+
Reddish-brown
What colour precipitate will be created when sodium hydroxide is added to Cu 2+
Blue
What colour will the flame go if you add lithium?
Red
What colour will the flame go if you add sodium?
Yellow
What colour will the flame go if you add potassium?
Lilac
What colour will the flame go if you add calcium?
Orange-red
What colour will the flame go if you add copper?
Blue-green
Describe how to do a flame test
1) clean a platinum flake test loop in HCl to remove traces of other chemicals
2) dip the loop in the solution/substance you are testing
3) hold in a roaring flame and observe colour change
What is the test for oxygen?
A glowing splint relights
What is the test for hydrogen ?
When lit it gives a squeaky pop