On heating $KMnO_4$,which one of the following is not formed?

Which of the following is the correct formula for a compound of scandium and oxygen?

Thermal decomposition of a $Mn$ compound $(X)$ at $513 \ K$ results in compound $Y$,$MnO_2$ and a gaseous product. $MnO_2$ reacts with $NaCl$ and concentrated $H_2SO_4$ to give a pungent gas $Z$. Identify $X, Y$ and $Z$.

Stainless steel is non-corrosive. This character is more prominent in

The spin only magnetic moment $(\mu)$ value $(B.M.)$ of the compound with strongest oxidising power among $Mn_2O_3$,$TiO$,and $VO$ is $....$ $B.M.$ (Nearest integer).

$CrO_3$ is a/an ...