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 $Sn = 118.7 \ g/mol$)

Balance the following redox reactions using the oxidation number and ion-electron method:
$(1) H_2S + Fe^{3+} \to Fe^{2+} + S + H^{+}$
$(2) Cu + NO_3^{-} \to Cu^{2+} + NO_2$
$(3) Sn + NO_3^{-} + H^{+} \to Sn^{2+} + NH_4^{+} + H_2O$
$(4) As + NO_3^{-} + H^{+} \to AsO_4^{3-} + NO_2 + H_2O$

For the decolourization of $1 \ mole$ of $KMnO_4$,the moles of $H_2O_2$ required is: (in $.5$)

$C +$ Conc. $H_2SO_4 \xrightarrow{\Delta} X + Y + H_2O$. $X$ and $Y$ in the above reaction are:

Treatment of alkaline $KMnO_{4}$ solution with $KI$ solution oxidises iodide to:

Which product is obtained during the reaction of $MnO_4^-$ with $I^-$ in a faintly alkaline condition?