Question

Using the standard electrode potentials given in the Table 8.1, predict if the reaction between the following is feasible: 

(a) Fe³⁺_(aq) and I_{^– (aq)} 

(b) Ag⁺_(aq) and Cu_(s) 

(c) Fe³⁺ _(aq) and Cu_(s) 

(d) Ag_(s) and Fe³⁺_(aq) 

(e) Br²_(aq) and Fe²⁺_(aq) 

Answer 1

Answer: We have

(a) The possible reaction between  Fe³⁺_(aq) +  I^-_(aq) 

2Fe^3-  +  2I^- _(aq)   →    2Fe²⁺  +  I_2(s)         is given by,

E° for the overall reaction is positive. Thus, the reaction between  Fe³⁺_(aq) and  I^-_(aq) is feasible

(b) The possible reaction between  Ag⁺_(aq)  +  Cu_(s) is given by, 

E° positive for the overall reaction is positive. Hence, the reaction between  Ag⁺_(aq) and Cu_(s) is feasible. 

 (c) The possible reaction between Fe³⁺_(aq) and  Cu_(s)  is given by, 

E° positive for the overall reaction is positive. Hence, the reaction between Fe³⁺_(aq) and Cu_(s) is feasible.

 (d) The possible reaction between Ag(s) and  Fe³⁺_(aq)

Here, E° for the overall reaction is negative. Hence, the reaction between Ag_(s) and Fe³⁺_(aq) is not feasible. 

(e) The possible reaction between Br_2(aq) and Fe²⁺_(aq) is given by, 

Here, E° for the overall reaction is positive. Hence, the reaction between Br_2(aq) and Fe²⁺_(aq) is feasible