In the following reaction $yMnO_4^- + xH^{+} + C_2O_4^{2-} \to yMn^{2+} + 2CO_2 + \frac{x}{2}H_2O$,the values of $x$ and $y$ are:

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

Acidified potassium dichromate on reacting with a sulphite is reduced to

$KMnO_4$ in basic medium is reduced to

In acidic medium,dichromate ion oxidises ferrous ion to ferric ion. If the gram molecular weight of potassium dichromate is $294 \ g$,its gram equivalent weight is $...$ grams.

Balance the following ionic equations:
$1. Cr_{2}O_{7}^{2-} + H^{+} + I^{-} \to Cr^{3+} + I_{2} + H_{2}O$
$2. Cr_{2}O_{7}^{2-} + Fe^{2+} + H^{+} \to Cr^{3+} + Fe^{3+} + H_{2}O$
$3. MnO_{4}^{-} + SO_{3}^{2-} + H^{+} \to Mn^{2+} + SO_{4}^{2-} + H_{2}O$
$4. MnO_{4}^{-} + H^{+} + Br^{-} \to Mn^{2+} + Br_{2} + H_{2}O$