The purple colour of $KMnO_4$ is due to the transition:

Match the aqueous solutions given in List-$I$ with their colors given in List-$II$:

List-$I$ (Aqueous solution of salt)	List-$II$ (Color)
$A$. $FeSO_4 \cdot 7H_2O$	$i$. Green
$B$. $NiCl_2 \cdot 4H_2O$	$ii$. Pale pink
$C$. $MnCl_2 \cdot 4H_2O$	$iii$. Blue
$D$. $CoCl_2 \cdot 6H_2O$	$iv$. Light green
$E$. $Cu_2Cl_2$	$v$. Pink
	$vi$. Colorless

Write about the utility of $d$- and $f$-block elements and their compounds. Or describe the following uses of $d$- and $f$-block elements and their compounds: $(i)$ In iron/steel $(ii)$ As pigments $(iii)$ In batteries $(iv)$ In coinage $(v)$ As catalysts.

What are the oxidation states of iron in the minerals hematite and magnetite?

$A$ metal $M$ which is not affected by strong acids like conc. $HNO_3$,conc. $H_2SO_4$ and conc. solutions of alkalies like $NaOH$,$KOH$ forms $MCl_3$,which finds use for toning in photography. The metal $M$ is:

The yellow colour solution of $Na_2CrO_4$ changes to orange-red on passing $CO_2$ gas due to the formation of