In the reduction of dichromate by $Fe(II)$,the number of electrons involved per chromium atom is:

In the balanced chemical equation $MnO_4^- + Br^- + H_2O \to MnO_2 + BrO_3^- + OH^-$,the coefficients of $MnO_4^-$,$BrO_3^-$,and $OH^-$ are respectively:

Assign $A$,$B$,$C$,$D$ from the given type of reaction.
$CuSO_4 + Zn_{(s)} \longrightarrow ZnSO_4 + Cu$

On balancing the given redox reaction,$aCr_2O_7^{2-} + bSO_3^{2-}{(aq)} + cH^{+}{(aq)}$ $\rightarrow 2aCr^{3+}{(aq)} + bSO_4^{2-}{(aq)} + \frac{c}{2}H_2O_{(l)}$,the coefficients $a$,$b$,and $c$ are found to be,respectively-

Balance the following ionic equations:
$1. Cr_{2}O_{7}^{2-} + H^{+} + I^{-} \to Cr^{3+} + I_{2} + H_{2}O$
$2. Cr_{2}O_{7}^{2-} + Fe^{2+} + H^{+} \to Cr^{3+} + Fe^{3+} + H_{2}O$
$3. MnO_{4}^{-} + SO_{3}^{2-} + H^{+} \to Mn^{2+} + SO_{4}^{2-} + H_{2}O$
$4. MnO_{4}^{-} + H^{+} + Br^{-} \to Mn^{2+} + Br_{2} + H_{2}O$

The reaction,$K_2Cr_2O_7 + m \, FeSO_4 + n \, H_2SO_4 \longrightarrow Cr_2(SO_4)_3 + p \, Fe_2(SO_4)_3 + K_2SO_4 + q \, H_2O$ when balanced,$m, n, p$ and $q$ are,respectively: