# Calculate the sta

(i) Known - E0Cr3 + /Cr = - 0.74 V

E0Cd2 + /Cd = - 0.40 V

rG0 = ?

K = ?

The galvanic cell of the given reaction is written as -

Cr(s)|Cr3 + (aq)|| Cd2 + (aq)|Cd(s) Reaction 1

Hence, the standard cell potential is given as,

E0 = E0R - E0L

= - 0.40 - (- 0.74)

E0 = + 0.34 V

To calculate the standard Gibb’s free energy, ∆rG0, we use,

rG0 = - nE0F Equation 1

where nF is the amount of charge passed and E0 is the standard reduction electrode potential.

Substituting n = 6 (no. of e - involved in the reaction 1), F = 96487 C mol-1,

E0 = + 0.34 V in Equation 1, we get,

rG0 = - 6×0.34V×96487 C mol-1

= - 196833.48 CV mol-1

= - 196833.48 J mol-1

rG0 = - 196.83348 kJ mol-1

To find out the equilibrium constant, K, we use the formula,  log K = 34.5177

K = antilog 34.5177

K = 3.294 × 1034

The standard Gibb’s free energy, ∆rG0 is - 196.83348 kJ mol – 1 and equilibrium constant, K is 3.294 × 1034

(ii) Known -

E0Fe3 + /Fe2 + = 0.77V

E0Ag + /Ag = 0.80 V

rG0 = ?

K = ?

The galvanic cell of the given reaction is written as -

Fe2 + (aq)|Fe3 + (aq)|| Ag + (aq)|Ag(s) Reaction 1

Hence, the standard cell potential is given as,

E0 = E0R - E0L

= 0.80 - (0.77)

E0 = + 0.03 V

To calculate the standard Gibb’s free energy, ∆rG0, we use,

rG0 = - nE0F Equation 1

where nF is the amount of charge passed and E0 is the standard reduction electrode potential.

Substituting n = 1 (no. of e - involved in the reaction 1), F = 96487 C mol-1, E0 = + 0.03V in Equation 1, we get,

rG0 = - 1×0.03V×96487 C mol-1

= - 2894.61 CV mol - 1

= - 2894.61 J mol-1

rG0 = - 2.89461 kJ mol-1

To find out the equilibrium constant, K, we use the formula,  log K = 0.5076

K = Antilog 0.5076

K = 3.218

The standard Gibb’s free energy, ∆rG0 is - 2.89461 kJ mol – 1 and equilibrium constant, K is 3.218

Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
Try our Mini CourseMaster Important Topics in 7 DaysLearn from IITians, NITians, Doctors & Academic Experts
Dedicated counsellor for each student
24X7 Doubt Resolution
Daily Report Card
Detailed Performance Evaluation view all courses RELATED QUESTIONS :

Consider the Fig.Chemistry - Exemplar

Assertion : CoppeChemistry - Exemplar

Note : In the folChemistry - Exemplar

Note : In the folChemistry - Exemplar

Match the items oChemistry - Exemplar

Note : In the folChemistry - Exemplar

Assertion : CurreChemistry - Exemplar

Assertion : ElectChemistry - Exemplar

Which reference eChemistry - Exemplar