Which of the following metal nitrate produces a gaseous product when it reacts with a $KCN$ solution?

How many grams of $Mg$ is required to completely reduce $100 \ mL$ of $0.1 \ M$ $NO_3^{-}$ solution using the following reaction:
$NO_3^{-} + Mg \longrightarrow Mg^{2+} + NH_3$

Explain the balancing of a redox reaction by the oxidation number method.

Which of the following reactions involves oxidation-reduction?

One mole of potassium dichromate completely oxidises the following number of moles of ferrous sulphate in acidic medium.

For the reaction $Cr_{2}O_{7}^{2-} \xrightarrow{H^{+}} Cr^{3+}$,the equivalent weight of $Cr_{2}O_{7}^{2-}$ is: