10 - Chemical Analysis Flashcards
How would you test for oxygen?
Relights a glowing splint
How would you test for carbon dioxide?
Turns lime water cloudy
How would you test for ammonia?
Damp red litmus paper will turn blue (heat the test solution to get ammonia gas)
How would you test for hydrogen?
Squeaky pop when a lighted splint is placed into a test tube with hydrogen
How would you test for chlorine?
If you put a damp blue litmus paper into a test tube with chlorine, it will bleach the damp blue litmus paper.
How would you carry out a flame test?
- Heat up a nichrome wire on the edge of a roaring blue flame.
- Let it cool down slightly.
- Dip it into HCl and then into the salt to be tested.
- Put this back on the edge of the roaring blue flame and observe the colour.
What is the colour of flame of Lithium?
red
What is the colour of flame of sodium?
yellow
What is the colour of flame of potassium?
lilac
What is the colour of flame of calcium?
orange-red
What is the colour of flame of copper?
blue-green
How would you test for cations?
- Dissolve salt into distilled water
- Add a few drops of sodium hydroxide
- Observe the colour of the precipitate
What is the colour of precipitate of copper?
blue
What is the colour of precipitate of calcium?
white, no change in excess sodium hydroxide
What is the colour of precipitate of aluminium?
white, redissolves in excess sodium hydroxide