$KMnO_4$ acts as an oxidising agent in alkaline medium. When alkaline $KMnO_4$ is treated with $KI$,iodide ion is oxidized to

For the ionic reaction: $XBrO_3^{-} + YCr^{+3} + ZH_2O \rightarrow pBr_2 + qHCrO_4^{-} + rH^{+}$

$A$ $20.0 \,mL$ solution containing $0.2 \,g$ impure $H_2O_2$ reacts completely with $0.316 \,g$ of $KMnO_4$ in acidic solution. The purity of $H_2O_2$ (in $\%$) is........... (mol. wt. of $H_2O_2 = 34$; mol. wt. of $KMnO_4 = 158$)

In balancing the half-reaction $S_2O_3^{2-} \to S_{(s)}$,the number of electrons that must be added is:

In the reaction of oxalate with permanganate in acidic medium,the number of electrons involved in producing one molecule of $CO_2$ is

Consider the following statements:
In the chemical reaction:
$MnO_2 + 4HCl \to MnCl_2 + 2H_2O + Cl_2$
$(1)$ Manganese ion is oxidised
$(2)$ Manganese ion is reduced
$(3)$ Chloride ion is oxidised
$(4)$ Chloride ion is reduced.
Which of these statements are correct?