Q&A - Ask Doubts and Get Answers
Q

Calculate the standard cell potentials of galvanic cell in which the following reactions take place:

3.4     Calculate the standard cell potentials of galvanic cell in which the following reactions take place:

           2Cr(s)+3Cd^{2+}(aq)\rightarrow 2Cr^{3+}(aq)+3Cd

       Calculate the \Delta _{r}G^{e} and equilibrium constant of the reactions.

     

      

Answers (1)
Views

The galvanic cell of the given reaction is shown below:- 

                                                     

The standard electrode potential of Cr and Cd can be found in table of standard electrode potential.

So, we get  :  

                                                 E^{\circ} = E^{\circ}_R\ -\ E^{\circ} _L

                                                         = -0.40\ -\ (-0.74)

                                                          =\ 0.34\ V

Now                             

                                            \Delta G_r^{\circ}\ = -\ nFE_{cell}^{\circ}

Putting values : 

                                            \Delta G_r^{\circ}\ = -\ 6\times96487\times 0.34

                                                         = -196.83\ KJ\ mol^{-1}

Now for finding equlilibrium constant we have : 

                                            log\ k = \frac{-\Delta G _r^{\circ}}{2.303\times R\times T}

or                                         log\ k = 34.496

or                                             K = 3.13\times10^34 

Exams
Articles
Questions