The reaction of aqueous $KMnO_4$ with $H_2O_2$ in acidic conditions gives

When $SO_{2}$ is passed through acidified $K_{2}Cr_{2}O_{7}$,the process that takes place is

Chlorine is used to purify drinking water. Excess of chlorine is harmful. The excess of chlorine is removed by treating with sulphur dioxide. Present a balanced equation for this redox change taking place in water.

$A_2O_x$ is oxidised to $AO_3^-$ by $MnO_4^-$ in acidic medium. If $1.5 \times 10^{-3} \text{ mole of } A_2O_x$ requires $40 \text{ mL}$ of $0.03 \text{ M } KMnO_4$ solution in acidic medium,which of the following statement$(s)$ is/are correct?

Assign $A$,$B$,$C$,$D$ from the given type of reaction.
$Cl_{2(g)} + 2KI(aq.) \longrightarrow 2KCl(aq.) + I_2(s)$

Observe the following reaction: $I_2 + 10 HNO_3 \rightarrow 2 HIO_3 + 10 NO_2 + 4 H_2O$. The equivalent weight of $HNO_3$ is (molar mass of $HNO_3 = M$).