When $SO_2$ gas is passed through an acidified solution of $K_2Cr_2O_7$,the solution turns........

Which of the following is not a redox reaction?

In the following reaction mixtures,
$I$. $Cu / CuSO_4 + Ag / Ag_2SO_4$
$II$. $Zn / ZnSO_4 + Cu / CuSO_4$
copper respectively undergoes

Assign $A, B, C, D$ from the given type of reaction.
$Ba(OH)_2 + CO_2 \longrightarrow BaCO_3 \downarrow + H_2O$

How much volume of $5 \ M$ $HNO_3$ is required to oxidize $16 \ g$ of $Fe^{+2}$ if $HNO_3$ is converted into $NO$? (Answer in $mL$)

Identify whether the following reactions act as oxidation or reduction processes:
$(i)$ $FeSO_4 + Mg \to MgSO_4 + Fe$
$(ii)$ $Cu + 4HNO_3 \to Cu(NO_3)_2 + 2NO_2 + 2H_2O$
$(iii)$ $H_2S + Cl_2 \to S + 2HCl$