Some Metals Form a Coloured Precipitate with NaOH Flashcards
1
Q
What are many metal hydroxides and what do they do when formed?
A
Insoluble and precipitate out of solution when formed
2
Q
What do some of these hydroxides have?
A
A characteristic colour
3
Q
What do you do in this test?
A
Add a few drops of sodium hydroxide solution to a solution of the mystery compound in a test tube
4
Q
How can you tell which metal was in the compound?
A
If you get a coloured insoluble hydroxide
5
Q
Copper(II)
A
Blue: Cu²+ + 2OH- —> Cu(OH)2
6
Q
Iron(II)
A
Sludgy green: Fe²+ + 2OH- —> Fe(OH)2
7
Q
Iron(III)
A
Reddish brown: Fe³ + 3OH- —> Fe(OH)3
