compound colours Flashcards
1
Q
observation when Cu2+ reacts with NaOH
A
- blue ppt forms
- insoluble in excess NaOH
1
Q
Cu2+ ion solution colour
A
blue
2
Q
equation for Cu2+ and NaOH
A
Cu2+ + 2OH- –> Cu(OH)2
3
Q
Fe2+ ion solution colour
A
pale green
4
Q
observation when Fe2+ reacts with NaOH
A
- green ppt forms
- insoluble in excess NaOH
- ppt turns brown in air
5
Q
equation for Fe2+ and NaOH
A
Fe2+ + 2OH- –> Fe(OH)2
6
Q
equation for Fe(OH)2 and air
A
Fe(OH)2 –> Fe(OH)3
7
Q
Fe3+ ion colour
A
pale yellow
8
Q
observation when Fe3+ reacts with NaOH
A
- brown ppt forms
- insoluble in excess NaOH
9
Q
equation for Fe3+ and NaOH
A
Fe3+ + 3OH- –> Fe(OH)3
10
Q
Mn2+ ion solution colour
A
pale pink
11
Q
observation when Mn2+ reacts with NaOH
A
- brown ppt forms
- ppt darkens in air
- insoluble in excess NaOH
12
Q
equation for Mn2+ and NaOH
A
Mn2+ + 2OH- –> Mn(OH)2
13
Q
Cr3+ ion solution colour
A
violet
14
Q
observation when Cr3+ reacts with NaOH
A
- grey green ppt forms
- ppt is soluble in excess NaOH to form dark green solution
