Which among the following species acts as a self-indicator?

Balance the following equations in basic medium by ion-electron method and oxidation number methods and identify the oxidising agent and the reducing agent.
$(a)$ $P_{4(s)} + OH_{(aq)}^{-} \to PH_{3(g)} + HPO_{2(aq)}^{-}$
$(b)$ $N_{2}H_{4(l)} + ClO_{3(aq)}^{-} \to NO_{(g)} + Cl_{(g)}^{-}$
$(c)$ $Cl_{2}O_{7(g)} + H_{2}O_{2(aq)} \to ClO_{2(aq)}^{-} + O_{2(g)} + H^{+}$

Identify the correct statement for the reaction: $I_2 + KClO_3 \xrightarrow{\Delta} ICl + KIO_3$

Find the values of $x$ and $y$ for the following balanced equation:
$xCl_2 + 6OH^- \to ClO_3^- + yCl^- + 3H_2O$

In alkaline medium,$MnO_4^{-}$ oxidises $I^{-}$ to:

Which of the following is a redox reaction?