Using the standard electrode potentials given in Table, predict if the reaction between the following is feasible`:`
`a. Fe^(3+)(aq)` and `I^(c-)(aq)`
`b.` `Ag^(o+)(aq)` and `Cu(s)`
`c.` `Fe^(3+)(aq)` and `Br^(c-)(aq)`
`d.` `Ag(s)` and `Fe^(3+)(aq)`
`e. ``Br_(2)(aq)` and `Fe^(2+)(aq)`.

Explanation

A reaction feasible if EMF of the cell reaction is +ve
(i) `Fe^(3+)(aq)+I^(-)(aq)toFe^(2+)(aq)+(1)/(2)I_(2)` i.e., `Pt|I_(2)|I^(-)(aq)||Fe^(3+)(aq)|Fe^(2+)(aq)|Pt`
`thereforeE_(cell)^(@)=E_(Fe^(3+),Fe^(2+))^(@)-E_(1//2I_(2),I^(-))^(@)=0.77-0.54=0.23V` (Feasible)
(ii) `Ag^(+)(aq)+CutoAg(s)+Cu^(2+)(aq),` i.e., `Cu|Cu^(2+)(aq)||Ag^(+)(aq)|Ag`
`E_(cell)^(@)+E_(Ag^(+),Ag^(-))^(@)-E_(Cu^(2+),Cu)^(@)=0.80-0.34=0.46V` (Feasible)
(iii) `Fe^(3+)(aq)+Br^(-)(aq)toFe^(2+)(aq)+(1)/(2)Br_(2),E_(cell)^(@)=0.77-1.09=-0.32V` (Not feasible)
(iv) `Ag(s)+Fe^(3+)(aq)toAg^(+)(aq)+Fe^(2+)(aq)E_(cell)^(@)=0.77-0.80=-0.03V` (Not feasible)
(v) `(1)/(2)Br_(2)(aq)+Fe^(2+)(aq)toBr^(-)+Fe^(3+),E_(cell)^(@)=1.09-0.77=0.32V` (Feasible)