The Eo values of the following reduction reactions are given: F e3+(a q)+e- arrow F e2+(a q), Eo=0.771 V F e2+(a q)+2 e- arrow F e(s), Eo=-0.447 V What will be the free energy change for the reaction? Fe 3+( aq )+3 e- arrow Fe ( s )( F =96485 C mol -1)

Question

The Eo values of the following reduction reactions are given: F e3+(a q)+e- arrow F e2+(a q), Eo=0.771 V F e2+(a q)+2 e- arrow F e(s), Eo=-0.447 V What will be the free energy change for the reaction? Fe 3+( aq )+3 e- arrow Fe ( s )( F =96485 C mol -1) (A) +18.51 kJ mol -1 (B) +11.87 kJ mol -1 (C) -8.10 kJ mol -1 (D) -10.41 kJ mol -1

Tardigrade Admin · Accepted Answer

F e2++2 e- arrow F e ; n1=2, E1o=-0.447 V F e3++e- arrow F e2+ ; n2=1, E2o=0.771 V F e3++3 e- arrow F e ; n3=3, E3o=? Δ G3=Δ G1+Δ G2 3 E3o=-2 E1o+E2o E3o=((-0.477 × 2)+0.771/3)=-0.041 V Δ Go=-n F Eo Δ Go=-3 × 96485 ×(-0.041 V ) Δ Go=+11867.65 mol -1 ≃+11.87 kJ mol -1

$+ 18.51 k J m o l^{- 1}$

$+ 11.87 k J m o l^{- 1}$

$- 8.10 k J m o l^{- 1}$

$- 10.41 k J m o l^{- 1}$

Q. The Eo values of the following reduction reactions are given: Fe3+(aq)+e−→Fe2+(aq),Eo=0.771V Fe2+(aq)+2e−→Fe(s),Eo=−0.447V What will be the free energy change for the reaction? Fe3+(aq)+3e−→Fe(s)(F=96485Cmol−1)

+18.51kJmol−1

+11.87kJmol−1

−8.10kJmol−1

−10.41kJmol−1

Fe2++2e−→Fe;n1​=2,E1o​=−0.447V Fe3++e−→Fe2+;n2​=1,E2o​=0.771V Fe3++3e−→Fe;n3​=3,E3o​=? ΔG3​=ΔG1​+ΔG2​3E3o​=−2E1o​+E2o​ E3o​=3(−0.477×2)+0.771​=−0.041VΔGo=−nFEo ΔGo=−3×96485×(−0.041V) ΔGo=+11867.65mol−1≃+11.87kJmol−1

$+ 18.51 k J m o l^{- 1}$

$+ 11.87 k J m o l^{- 1}$

$- 8.10 k J m o l^{- 1}$

$- 10.41 k J m o l^{- 1}$