Which from the following alloys is used in gas turbine engines?

The highest stable $Mn$ fluoride is $MnF_4$,whereas the highest $Mn$ oxide is $Mn_2O_7$. This is due to:

Acidified chromic acid $+ H_2O_2 \xrightarrow{\text{Org. solvent}} X + Y$ (blue colour). $X$ and $Y$ are:

When $MnO_2$ is fused with $KOH$ in the presence of air,a colored compound is formed. Identify the compound and its color.

Ferric sulphate on heating gives:

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: