tests Flashcards
What is the test for Lithium, Sodium, Potassium and Calcium?
these are cations/positive ions
- make a solution of the metal compound.
- put a bunsen burner on a blue flame.
- Clean a piece of nichrome wire by dipping it in acid and then place it into the flame until no colour is seen.
- Dip the clean nichrome wire into the metal compound solution and place it in the flame.
observe the colour change.
What colour does Potassium go in the flame test?
Lilac
What colour does Lithium go in the flame test?
Scarlet/Crimson
What colour does calcium go in the flame test?
Brick Red
What colour does Sodium go in the flame test?
yellow
What is the test for Ammonium?
- Start with a solution of the compound.
- add sodium hydroxide
- warm it gently
- test any gas that is made with damp red litmus paper
- If the damp red litmus paper goes blue then the gas was ammonia and therefore ammonium ions are present.
What is the test for Coppper(II), Iron (II) and Iron (III)
hydroxide ions
- Place a small amount of the metal solution in a test tube.
- Add a small amount of sodium hydroxide.
- Observe the colour of the precipitate.
What colour does Copper (II) precipitate go?
Blue
What colour does Iron (II) precipitate go?
green
What colour does Iron (III) precipitate go?
orangey brown
What is the test for the halides?
- Add nitric acid to check it is not a carbonate.
2. Add silver nitrate and observe the colour of the precipitate
What colour does Chlorine go in the halide test?
white
What colour does bromine go in the halide test?
cream
what colour does iodine go in the halide test?
yellow
What is the test for sulphate ions?
Test: Add hydrochloric acid to check it is not a carbonate.
Add a few drops of Barium chloride solution
Result: White precipitate (Barium sulphate)