Which of the following reactions is $NOT$ an intermolecular redox reaction?

When $KMnO_4$ solution is titrated with a solution containing $Fe^{2+}$ ions,the indicator used in this titration is

Assign $A, B, C, D$ from the given type of reaction.
$AgNO_3 \,(Solution) + NaF \,(Solution) \longrightarrow$ No reaction

Balance the following equations by the oxidation number method:
$(a) Fe^{+2} + H^{+} + Cr_2O_7^{-2} \to Cr^{+3} + Fe^{+3} + H_2O$
$(b) I_2 + NO_3^- \to NO_2 + IO_3^-$
$(c) I_2 + S_2O_3^{-2} \to I^{-} + S_4O_6^{-2}$
$(d) MnO_4^- + C_2O_4^{-2} \to Mn^{+2} + CO_2$

When silver nitrate is heated to red hot,what is formed?

When $SO_2$ is bubbled into an acidic $KMnO_4$ solution,decolorization of the purple solution takes place along with the formation of a manganese compound $X$. Under neutral conditions,compound $X$ reacts with $KMnO_4$ in the presence of zinc oxide to give another manganese compound $Y$. The oxidation states of manganese in compounds $X$ and $Y$,respectively,are