What is the charge required to convert $2 \ mol$ of $KMnO_4$ to $MnSO_4$ (in $F$)?

Metallic tin in the presence of $HCl$ is oxidized by $K_2Cr_2O_7$ to stannic chloride. What volume of decinormal dichromate solution would be reduced by $1 \ g$ of tin? (Atomic weight of $Sn = 118.7 \ g/mol$)

The oxidation state of chromium in the final product formed by the reaction between $KI$ and acidified potassium dichromate solution is

In the redox reaction $N_2H_4 + ClO_3^- \to NO + Cl^-$ (in basic medium),how many electrons are added in the reduction half-reaction based on the difference in oxidation states?

Aqueous solutions of hydrogen sulphide and sulphur dioxide when mixed together,yield

Assign $A, B, C, D$ from the given type of reaction.
$3PbS + 8HNO_3 \text{ (dil.)} \longrightarrow 3Pb(NO_3)_2 + 3S \downarrow + 2NO + 4H_2O$