Chemical tests Flashcards
1
Q
Hydrogen
A
- Ignite with a lite splint
- Produces a “squeaky” pop
2
Q
Oxygen
A
- Glowing splint
- Relights
3
Q
Carbon dioxide
A
- Bubble through limewater
- Goes cloudy/milky
4
Q
Ammonia
A
- Damp red litmus paper
- Goes blue
5
Q
Chlorine
A
- Damp blue litmus paper
- Bleaches (goes white)
6
Q
Cations (positive ions)
A
Everything is either flame test or addition of sodium hydroxide solution
7
Q
Flame test practical
A
- Use a clean nichrome wire by dipping in concentrated hydrochloric acid. (reason: impurities/any substance on it may affect the flame colour)
- Nichrome wire – does not melt, does not colour the flame and is unreactive.
- To put the solid in a non-luminous Bunsen flame (non-luminous flame is used so
colour can be easily seen and also hot enough to produce a flame colour.)
8
Q
Flame test practical
A
- Use a clean nichrome wire by dipping in concentrated hydrochloric acid. (reason: impurities/any substance on it may affect the flame colour)
- Nichrome wire – does not melt, does not colour the flame and is unreactive.
- To put the solid in a non-luminous Bunsen flame (non-luminous flame is used so
colour can be easily seen and also hot enough to produce a flame colour.)
9
Q
What colour is sodium?
A
Yellow
10
Q
What colour is potassium?
A
Lilac
11
Q
What colour is calcium?
A
Orange-red
12
Q
What colour is lithium?
A
Red
13
Q
What colour is copper?
A
Blue-green
14
Q
Test for Ammonium ions (NH4 +)
A
- Add sodium hydroxide solution and warm.
- Test ammonia gas produced with damp red litmus paper. Turns blue.
NH3 + H2O - NH4 + OH-
15
Q
Ammonium ions (NH4+)
A
- Add sodium hydroxide solution and warm.
- Test ammonia gas produced with damp red litmus paper. Turns blue.
NH3 + H2O - NH4 + OH-
