When $SO_{2}$ is passed through acidified $K_{2}Cr_{2}O_{7}$,the process that takes place is

In an acidic medium,the dichromate ion oxidizes the ferrous ion to the ferric ion. If the molar mass of potassium dichromate is $294 \, g/mol$,what is its equivalent mass?

Assign $A$,$B$,$C$,$D$ from the given type of reaction.
$2NaBr + MnO_2 + 2H_2SO_4 \longrightarrow MnSO_4 + Na_2SO_4 + Br_2 + 2H_2O$

What is the equivalent mass of $IO_4^-$ when it is converted into $I_2$ in an acidic medium?

If the molecular weights of $Na_2S_2O_3$ and $I_2$ are $M_1$ and $M_2$ respectively, then what will be the equivalent weights of $Na_2S_2O_3$ and $I_2$ in the following reaction?
$2S_2O_3^{2-} + I_2 \longrightarrow S_4O_6^{2-} + 2I^-$

$1$ mole of $PbS$ is oxidised by "$X$" moles of $O_3$ to get "$Y$" moles of $O_2$. $X + Y = $ . . . . . . .