4.6.2 Cation tests Flashcards
1
Q
What are cations?
A
Positive ions.
2
Q
What flame should be used in a flame test?
A
A non-luminous flame.
3
Q
How do you conduct a flame test?
A
- Dip a piece of nichrome/platinum wire into HCl, this cleans the wire.
- Dip the wire into a sample.
- Place the tip of the wire into a non-luminous Bunsen burner flame.
4
Q
What is the test for Li+?
A
Red flame test.
5
Q
What is the test for Na+?
A
Yellow flame test.
6
Q
What’s the test for K+?
A
Lilac flame test.
7
Q
What’s the test for Ca2+?
A
Orange-red flame test.
8
Q
What’s the test for Cu2+? (flame test)
A
Blue-green flame test.
9
Q
How do you conduct an NaOH test?
A
- Dissolve the sample in water.
- Add a few drops of NaOH.
10
Q
What’s the test for Cu2+? (NaOH) And what ppt is formed?
A
Blue NaOH test, ppt formed is Cu(OH)2.
11
Q
What’s the test for Fe2+? And what’s the ppt formed?
A
Green NaOH test, ppt formed is Fe(OH)2.
12
Q
What’s the test for Fe3+? And what’s the ppt formed?
A
Brown NaOH test, ppt formed is Fe(OH)3.
13
Q
What’s the test for ammonium (NH4^+)
A
- Dissolve the sample in water.
- Add some NaOH and warm it.
- Test the gas evolved with damp red litmus paper. It should turn blue.
