Reaction of Manganese, Mn2+
Color : pale pink, almost colourless
| Test | Observations | Notes |
|---|---|---|
| Add NaOH(aq) | An off-white ppt is formed insoluble in xs NaOH and rapidly turning brown on contact with air | Off-white ppt is Mn(OH)2(s). In air it is rapidly oxidized to brown Mn(OH)3(s) The brown color of the ppt continues to darken due to dehydration to form Mn2O3(s) |
|
Add NH3
Fliter the solid and leave it in the air |
off-white ppt is formed insoluble in xs NH3 and rapidly turning brown on contact with air
Brown colour of ppt becomes deeper |
Off-white ppt is Mn(OH)2(s). In air it is rapidly oxidized to brown Mn(OH)3(s) The brown color of the ppt continues to darken due to dehydration to form Mn2O3(s) |