Question

For a certain reaction,   ΔH°=−14.6   kJ  and   ΔS°=−233  J/K.  If  n=2,  calculate  E°cell  for the reaction at  25°C.

a. −0.284 V

b. 0.0961 V

c. −0.130 V

d. 0.736 V

e. 0.0654 V

Answer 1

deltaH = -14.6 KJ/mol

deltaS = -233 J/mol.K

= -0.233 KJ/mol.K

T= 25.0 oC

= (25.0+273) K

= 298 K

we have below equation to be used:

deltaG = deltaH - T*deltaS

deltaG = -14.6 - 298.0 * -0.233

deltaG = 54.834 KJ/mol

Here number of electrons being transferred = 2

deltaG = 54.834 KJ/mol

deltaG = 54834.0 J/mol

F = 96500 C

we have below equation to be used:

deltaG = -n*F*E

54834= -2*96500.0*E

E = -0.284 V

Answer: a