chemical tests Flashcards
1
Q
describe the method of flame tests
A
- dip wire into nichrome wire into hydrochloric acid
- dip wire into a sample of solid
- place tip of wire into roaring flame of a bunsen burner
2
Q
what colour does Li+ produce in a flame test
A
red
3
Q
what colour does Na- produce in a flame test
A
yellow
4
Q
what colour does K+ produce in a flame test
A
Lilac
5
Q
what colour does Ca+ produce in a flame test
A
orange
6
Q
what colour does Cu+ produce in a flame test
A
green
7
Q
describe the method for forming precipitate
A
- dissolve sample in water
- add a few drops of NaOH
8
Q
what colour does the Cu2+ precipitate form
A
Blue
9
Q
what colour does the Fe2+ precipitate form
A
green
10
Q
what colour does the Fe3+ precipitate form
A
brown
11
Q
describe the test for ammonia
A
- dissolve sample in water
- add NaOH and heat it
- test gas with damp red litmus paper
- red litmus will turn blue if NH3 ions are present
12
Q
what is the test for hydrogen
A
- place lit splint into a tube of hydrogen
- will make a squeaky pop noise
13
Q
what is the test for oxygen
A
- place in a glowing splint into a tube
- splint will relight
14
Q
test for carbon dioxide
A
bubble through with limewater solution will turn cloudy
15
Q
test for chlorine
A
- bleaches damp blue litmus paper white
