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

$N_2H_4 + IO_3^- + 2H^+ + Cl^- \to ICl + N_2 + 3H_2O$. What is the equivalent weight of the reductant in the above reaction?

$50 \ cm^{3}$ of $0.04 \ M \ K_{2}Cr_{2}O_{7}$ in acidic medium oxidizes a sample of $H_{2}S$ gas to sulphur. The volume of $0.03 \ M \ KMnO_{4}$ required to oxidize the same amount of $H_{2}S$ gas to sulphur in acidic medium is: (in $cm^{3}$)

Assign $A, B, C, D$ from the given type of reaction.
$KMnO_4 + NaNO_3 \longrightarrow$ No reaction

How many moles of $H_2SO_3$ are required to reduce one mole of $KMnO_4$ in an acidic medium?

The treatment of an aqueous solution of $3.74 \ g$ of $Cu(NO_3)_2$ with excess $KI$ results in a brown solution along with the formation of a precipitate. Passing $H_2S$ through this brown solution gives another precipitate $X$. The amount of $X$ (in $g$) is. . . . . [Given : Atomic mass of $H=1, N=14, O=16, S=32, K=39, Cu=63, I=127$ ]