question_answer 1)

  \[{{E}^{O-}}\]values of some redox couples are given below. On the basis of these values choose the correct option. \[{{E}^{O-}}\]values: \[B{{r}_{2}}/B{{r}^{-}}=+1.90;A{{g}^{+}}/Ag(s)=+0.80;\] \[C{{u}^{2+}}/Cu(s)=+\,0.34;{{I}_{2}}(s)/{{I}^{-}}=+0.54\] (a) Cu will reduce \[B{{r}^{-}}\]                                                  (b) Cu will reduce\[\text{Ag}\] (c) Cu will reduce \[{{I}^{-}}\]                                                     (d) Cu will reduce \[B{{r}_{2}}\]

Answer:

  (d)\[Cu+B{{r}_{2}}\to C{{u}^{2+}}+2B{{r}^{-}}\] \[E_{\operatorname{Re}dox\,process}^{{}^\circ }=E_{\operatorname{Re}duced\,species}^{{}^\circ }-E_{OXidised\,species}^{{}^\circ }\] \[=+1.90-(+0.34)=+1.56V\] Positive value shows that the redox process is feasible.