The number of moles of electrons required to reduce $0.2 \ mol$ of $Cr_2O_7^{2-}$ to $Cr^{3+}$ is:

Which of the following reactions involves both oxidation and reduction?

Observe the following stoichiometric equation:
$P_4 + 3 OH^{-} + 3 H_2 O \rightarrow PH_3 + 3 X^{-}$
What is the conjugate acid of $X^{-}$?

For the redox reaction $xP_4 + yHNO_3 \to H_3PO_4 + NO_2 + H_2O$,find the values of $x$ and $y$.

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.

The product of $I^-$ with $MnO_4^-$ in alkaline medium is