When chlorine gas is passed through an aqueous solution of $KBr$,the solution turns orange brown due to the formation of

What is the value of $x$ in order to balance the following redox reaction by the ion-electron method?
$x H_2O_2 + ClO_4^{-} \rightarrow x O_2 + ClO_2^{-} + 2 H_2O$

Balance the following redox reactions by the ion-electron method:
$(a)$ $MnO_{4(aq)}^- + I_{(aq)}^- \to MnO_{2(s)} + I_{2(s)}$ (in basic solution)
$(b)$ $MnO_{4(aq)}^- + SO_{2(g)} \to Mn_{(aq)}^{2+} + HSO_{4(aq)}^-$ (in acidic solution)
$(c)$ $H_2O_{2(aq)} + Fe_{(aq)}^{2+} \to Fe_{(aq)}^{3+} + H_2O_{(l)}$ (in acidic solution)
$(d)$ $Cr_2O_7^{2-} + SO_{2(g)} \to Cr_{(aq)}^{3+} + SO_{4(aq)}^{2-}$ (in acidic solution)

Aqueous solutions of hydrogen sulphide and sulphur dioxide when mixed together,yield

In acidic medium,the equivalent weight of $K_2Cr_2O_7$ $(mol. wt. = M)$ is

What is the equivalent weight of $K_2Cr_2O_7$ during the iodometric standardization of $Na_2S_2O_3$?