${\mathrm{H}}_3{\mathrm{PO}}_4$ is a tribasic acid and one of its salt is ${\mathrm{NaH}}_2{\mathrm{PO}}_4$. What volume of $1 \mathrm{M}$ $\mathrm{NaOH}$ solution should be added to $12 \mathrm{g}$ of ${\mathrm{NaH}}_2{\mathrm{PO}}_4$ to convert it into ${\mathrm{Na}}_3{\mathrm{PO}}_4$?

${\mathrm{Cr}}_2{\mathrm{O}}_7^{2-}+6{\mathrm{I}}^{-}+14{\mathrm{H}}^{+}⟶6{\mathrm{I}}_2+2{\mathrm{Cr}}^{3+}+7{\mathrm{H}}_2\mathrm{O}$

Which are not in balanced position?

${\mathrm{H}}_2\mathrm{S}+2{\mathrm{HNO}}_3\to 2{\mathrm{H}}_2\mathrm{O}+2{\mathrm{NO}}_2+\mathrm{S}$

The equivalent weight of nitric acid in the above reaction is

Two beakers, $\mathrm{A}$ and $\mathrm{B}$ each contain a nickel ion solution. A silver strip is dipped in beaker $\mathrm{A}$ and a copper strip is dipped in beaker $\mathrm{B}$.

Given that,

${\mathrm{E}}_{{\mathrm{Ni}}^{2+}/\mathrm{Ni}}^0=-0.25 \mathrm{V},$ ${\mathrm{E}}_{{\mathrm{Cu}}^{2+}/\mathrm{Cu}}^0=+0.34 \mathrm{V}$ and ${\mathrm{E}}_{{\mathrm{Ag}}^{2+}/\mathrm{Ag}}^0=0.80 \mathrm{V}$.

Based on the above information, which of the following is correct?

a) $$\begin{gathered} {\mathrm{Fe}}^{3+}+{\mathrm{e}}^{-}\to {\mathrm{Fe}}^{2+}\left(\mathrm{aq}\right) \\ {\mathrm{E}}^0=+0.77 \mathrm{V} \end{gathered}$$

b) $$\begin{gathered} {\mathrm{Al}}^{3+}+3{\mathrm{e}}^{-}\to \mathrm{Al}\left(\mathrm{s}\right) \\ {\mathrm{E}}^0=-1.66 \mathrm{V} \end{gathered}$$

c) $$\begin{gathered} {\mathrm{Br}}_2+2{\mathrm{e}}^{-}\to 2{\mathrm{Br}}^{-}\left(\mathrm{aq}\right) \\ {\mathrm{E}}^0=+1.08 \mathrm{V} \end{gathered}$$

Based on the data given above, what is the correct order of reducing power?