Which of the following compounds is amphoteric?

The false statement about iron $(III)$ hydroxide is that

The ionic charges on chromate ion and dichromate ion respectively are:

The colour imparted by $Co(II)$ compounds to glass is

Highest fluoride and highest oxide of $Mn$ are respectively

Preparation of potassium permanganate from $MnO_2$ involves a two-step process in which the $1^{st}$ step is a reaction with $KOH$ and $KNO_3$ to produce: