How many moles of electrons are required to reduce $2.5 \ mol$ of $Cr_2O_7^{2-}$ to $Cr^{3+}$?

Assign $A$,$B$,$C$,$D$ from the given type of reaction.
$K_2Cr_2O_7 \xrightarrow{\Delta } K_2CrO_4 + Cr_2O_3 + O_2 \uparrow$

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

$MnO_4^- + C_2O_4^{2-} + H^+ \to Mn^{2+} + CO_2 + H_2O$ :
What are the correct stoichiometric coefficients for the balanced redox reaction?

For the reaction:
$I^{-} + ClO_{3}^{-} + H_{2}SO_{4} \longrightarrow Cl^{-} + HSO_{4}^{-} + I_{2}$
The correct statement$(s)$ in the balanced equation is/are:
$A$. Stoichiometric coefficient of $HSO_{4}^{-}$ is $6$.
$B$. Iodide is oxidized.
$C$. Sulphur is reduced.
$D$. $H_{2}O$ is one of the products.

How many protons will be consumed when dichromate ion oxidises $Fe^{2+}$ ions in aqueous acidic medium?