$I.{\text{ }}2Cs{\text{ }} + {\text{ }}2{H_2}O{\text{ }} \to {\text{ 2}}CsOH{\text{ }} + {\text{ }}{H_2}$
$II.{\text{ }}2Cu{I_2} \to 2CuI + {\text{ }}{I_2}$
$III.{\text{ }}N{H_4}Br + {\text{ }}KOH \to KBr{\text{ }} + {\text{ }}N{H_3} + {\text{ }}{H_2}O$
$IV.{\text{ }}4KCN{\text{ }} + {\text{ }}Fe{\left( {CN} \right)_2} \to {K_4}\left[ {Fe{{\left( {CN} \right)}_6}} \right]$
$NO_3^ - + 4{H^ + } + {e^ - }\, \to \,2{H_2}O + NO$