Which of the following does not decolourise iodine?

$A$ sample $(5.6 \ g)$ containing iron is completely dissolved in cold dilute $HCl$ to prepare $250 \ mL$ of solution. Titration of $25.0 \ mL$ of this solution requires $12.5 \ mL$ of $0.03 \ M \ KMnO_4$ solution to reach the end point. The number of moles of $Fe^{2+}$ present in the $250 \ mL$ solution is $x \times 10^{-2}$ (consider complete dissolution of $FeCl_2$). The amount of iron present in the sample is $y \%$ by weight. (Assume: $KMnO_4$ reacts only with $Fe^{2+}$ in the solution. Use: Molar mass of iron as $56 \ g \ mol^{-1}$)
$(1)$ The value of $x$ is. . . . .
$(2)$ The value of $y$ is. . . . .

Which of the following is $NOT$ a redox reaction?

Which of the following decolourises the colour of acidic $KMnO_4$?

Assign $A$,$B$,$C$,$D$ from the given type of reaction.
$2BaCrO_4 \downarrow + 4HCl \longrightarrow 2BaCl_2 + H_2Cr_2O_7 + H_2O$

Upon the addition of a solution $A$ to a strongly acidified solution of barium nitrate,a white precipitate was obtained which did not dissolve even after large addition of water. Solution $A$ contained