$S _{8( s )}+ a OH ^{-}_{( aq )} \rightarrow b S ^{2-}_{( aq )}+ c S _{2} O _{3}{ }^{2-}{ }_{( aq )}+ d H _{2} O _{(\ell)}$

$'a'$ નું મૂલ્ય ............ છે. (પૂર્ણાક જવાબ)

$I.{\text{ }}2Cs{\text{ }} + {\text{ }}2{H_2}O{\text{ }} \to {\text{ 2}}CsOH{\text{ }} + {\text{ }}{H_2}$

$II.{\text{ }}2Cu{I_2} \to 2CuI + {\text{ }}{I_2}$

$III.{\text{ }}N{H_4}Br + {\text{ }}KOH \to KBr{\text{ }} + {\text{ }}N{H_3} + {\text{ }}{H_2}O$

$IV.{\text{ }}4KCN{\text{ }} + {\text{ }}Fe{\left( {CN} \right)_2} \to {K_4}\left[ {Fe{{\left( {CN} \right)}_6}} \right]$