$KMnO_4$ in basic medium is reduced to

When $SO_2$ gas is passed through an acidic solution of $K_2Cr_2O_7$,what is the change in the oxidation state of chromium?

The coefficients $x, y, p, q,$ and $r$ in the following balanced equation are respectively:
$xMnO_4^{2-}{_{\text{(aq)}}} + yH_2O_{\text{(l)}} \rightarrow pMnO_2{_{\text{(s)}}} + qMnO_4^{-}{_{\text{(aq)}}} + rOH^{-}{_{\text{(aq)}}}$

In alkaline medium,the reaction of hydrogen peroxide with potassium permanganate produces a compound in which the oxidation state of $Mn$ is $....$

In the balanced chemical equation $MnO_4^- + Br^- + H_2O \to MnO_2 + BrO_3^- + OH^-$,the coefficients of $MnO_4^-$,$BrO_3^-$,and $OH^-$ are respectively:

$Cr _2 O _7^{2-} \rightarrow Cr ^{3+}_{aq}$
How many moles of $Sn^{2+}$ will be oxidized by $1 \ mol \ Cr_2O_7^{2-}$ into $Sn^{4+}$?