cation tests Flashcards
1
Q
is a cation positive
A
yes
2
Q
examples of cations
A
Li+, Na+, K+, Ca2+, Cu2+, Fe2+, Fe3+, NH4+
3
Q
how to conduct a flame test
A
- dip a piece of nicrome/platinum wire into hydrochloric acid to clean it
- dip the wire into a sample of solid or solution
- place the tip of the wire into a NON-LUMINOUS bunsen flame
4
Q
what colour does Li+ turn
A
red
5
Q
what colour does Na+ turn
A
yellow
6
Q
what colour does K+ turn
A
lilac
7
Q
what colour does Ca2+ turn
A
orange-red
8
Q
what colour does Cu2+ turn
A
blue-green
9
Q
how to conduct an NaOH test (sodium hydroxide)
A
- dissolve the sample into water
- add a few drops of NaOH(aq)
10
Q
precipitate colour and formula of Cu2+
A
blue, Cu(OH)2
11
Q
precipitate colour and formula of Fe2+
A
green, Fe(OH)2
12
Q
precipitate colour and formula of Fe3+
A
brown, Fe(OH)3
