Short Answer TypeCalculate the number of unpaired electrons in following gaseous ions: Mn3+, Cr3+, V3+ and Ti3+, which one of these is the most stable in aqueous solution?
Give example and suggest reasons for the following features of the transition metal chemistry:
The lowest oxide of transition metal is basic, the highest is amphoteric/acidic.
Give example and suggest reasons for the following features of the transition metal chemistry:
A transition metal exhibits highest oxidation state in oxides and fluroides.
Give example and suggest reasons for the following features of the transition metal chemistry:
The highest oxidation state is exhibited in oxoanions of a metal.
Indicate the steps in the preparation of KMnO4 from pyrolusite ore.
Pottassium Permanganate (KMnO4) is prepared from Pyrolusite ore (MnO2). The finely powdered Pyrolusite ore (MnO2) is fused with an alkali metal hydroxide like KOH in the presence of air or an oxidizing agent like KNO3 to give the dark green potassium Manganate (K2MnO4). Potassium manganate disproportionate in a neutral or acidic solution to give potassium permanganate.
2 MnO2 + 4 KOH + O2 ----------> 2K2MnO4 + 2H2O
3 MnO42- + 4H+ ------------> 2MnO4- + MnO2 + 2H2O
Commercially potassium permanganate is prepared by the alkaline oxidative fusion ofPyrolusite ore (MnO2) followed by the electrolytic oxidation of manganate (4) ion.
2 MnO2 + 4KOH + O2 -----------> 2K2MnO4 + 2H2O
MnO42- ------(electrolytic oxidation)----> MnO4- + e-
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