Chemical Analysis - Inorganic Tests and UV-vis (10.2) Flashcards
1
Q
What colour is chlorine in organic solution?
A
- pale yellow
2
Q
What colour is bromine in organic solution?
A
- red/orange
3
Q
What colour is iodine in organic solution?
A
- magenta/purple
4
Q
What colour is chlorine in aqueous solution?
A
- pale green
5
Q
What colour is bromine in aqueous solution?
A
- orange-brown
6
Q
What colour is iodine in aqueous solution?
A
- pale brown
7
Q
How are halide ions identified?
A
- by reacting with silver nitrate
> AgCl, white
> AgBr, Cream
> AgI, Yellow
8
Q
How do you identify metal carbonates?
A
- by reacting with acid
- as carbon dioxide turns limewater milky
9
Q
What happens to group 2 metal hydroxides?
A
- solubility increases down the group
- how they are identified
- MgOH (milk of magnesia) = least soluble
10
Q
What happens to group 2 metal sulfates?
A
- solubility decreases down the group
- how they are identified
- BaSO4, used in a lot of medical applications/imaging - as it less soluble
11
Q
How are group 1 and 2 metal ions identified?
A
- by flame tests
12
Q
What are colour of the flame tests of group 1 + group 2 metals?
A
- lithium, red
- sodium, orange
- potassium, lilac
- rubidium, reddish violet
- caesium, blue-violet
- calcium, orange-red
- strontium, red
- barium, pale green
- copper, green-blue
13
Q
What happens inside the atom? (flames)
A
- heat of flame excites an electron + promotes an outer electron to a higher energy level
- excited atom relaxes back to ground state by releasing light energy
- ground (heat energy = absorbed) to excited (heat energy = released) to ground
14
Q
What does UV-Visible spectroscopy do?
A
- quantifies the colour of a solution by determining the colours of light that are absorbed
15
Q
What happens to wavelengths of light?
A
- some = absorbed
- most = transmitted (those seen by our eyes)
