1
Q
What is thermal decomposition?
A
-when a substance breaks down into at least two other substances when heated
2
Q
What happens when you heat a transition metal carbonate?
A
- break down into metal oxide and carbon dioxide
- this usually results in a colour change
3
Q
What are precipitations?
A
-when a solid forms in a solution
4
Q
What is a precipitation reaction?
A
-where two solution react and an insoluble solid form in the solution
5
Q
What happens if you react soluble transition metal compounds with sodium hydroxide?
A
- you get insoluble hydroxide
- which the precipitates out
6
Q
How can you use precipitations to test for transition metal ions?
A
- some insoluble transition metal hydroxides have different colours
- you can use this fact to test which transition metal ions a solution contains
- e.g. adding sodium hydroxide to an unknown soluble salt may result in an orange/brown precipitation, you know you have got iron(III) hydroxide and so have Fe3+ ions in he solution
7
Q
Name some transition metal hydroxides and their colours.
A
- copper(II) hydroxide=blue solid
- iron(II) hydroxide=green/grey solid
- iron(III) hydroxide=orange/brown solid
