The compounds formed when $KMnO_4$ is heated to $513 \ K$ are . . . . . .

The most basic hydroxide among the following is

Presence of $Cr$ in steel makes it

When a mixture of potassium dichromate and potassium chloride is heated with concentrated $H_2SO_4$,which of the following is produced as red vapors?

The conversion of pig iron to steel frequently requires the addition of
$(I)$ oxygen or iron oxide
$(II)$ transition elements
$(III)$ inner transition elements
$(IV)$ silica

Which of the following statements are $INCORRECT$?
$A$. All the transition metals except scandium form $MO$ oxides which are ionic.
$B$. The highest oxidation number corresponding to the group number in transition metal oxides is attained in $Sc_2O_3$ to $Mn_2O_7$.
$C$. Basic character increases from $V_2O_3$ to $V_2O_4$ to $V_2O_5$.
$D$. $V_2O_4$ dissolves in acids to give $VO_4^{3-}$ salts.
$E$. $CrO$ is basic but $Cr_2O_3$ is amphoteric.
Choose the correct answer from the options given below: