$KI$ is oxidised into $I_2$ by using the reagent

$H_2O_2$ reduces $KMnO_4$ in acidic medium to '$x$' and in basic medium to '$y$'. What are $x$ and $y$?

Which of the following is not a redox reaction?

$X + H_2SO_4 \to Y$ (colorless gas) and $Y + K_2Cr_2O_7 + H_2SO_4 \to$ green solution. Then $X$ and $Y$ are respectively ........

Thiosulphate reacts differently with iodine and bromine in the reactions given below:
$2 S_2 O_3^{2-} + I_2 \rightarrow S_4 O_6^{2-} + 2 I^{-}$
$S_2 O_3^{2-} + 4 Br_2 + 5 H_2 O \rightarrow 2 SO_4^{2-} + 8 Br^{-} + 10 H^{+}$
Which of the following statements justifies the above dual behaviour of thiosulphate?

Which of the following reactions are redox reactions?
$I. \, Cr_2O_7^{2-} + 2OH^- \to 2CrO_4^{2-} + H_2O$
$II. \, Zn + CuSO_4 \to ZnSO_4 + Cu$
$III. \, 2MnO_4^- + 3Mn^{2+} + 4OH^- \to 5MnO_2 + 2H_2O$
$IV. \, 2Cu^+ \to Cu + Cu^{2+}$