Which of the following is used as a white pigment?

The colour of the bead in the borax bead test is mainly due to the formation of:

Which of the following is a product of the first step and is used as a reactant in the next step for the manufacture of $K_{2}Cr_{2}O_{7}$ from concentrated chromite ore?

When $MnO_2$ is fused with solid $KOH$ in the presence of air,what is the product formed and its color?

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

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