Question

Calculate the standard cell potential at 25 ∘C for the reactionX(s)+2Y+(aq)→X2+(aq)+2Y(s)where ΔH∘ = -829 kJ and ΔS∘ = -367 J/K

Answer 1

The standard cell potential at 25 ∘C for the reaction is 2.72 Volts.

Step-by-step explanation:

Δ°G = Δ°H - TΔ°S (Gibb's equation)

Δ°G = Gibbs free energy

Δ°H = Enthalpy of the reaction at temperature T

Δ°S = Entropy of the reaction at temperature T

`\Delta G^o=-nfE^o_(cell)`

n = number of electrons transferred

F = Faraday's constant = 96500 C

`E^o_(cell)` = standard electrode potential of the cell

We have:

Δ°H = -829 kJ = -829000 J

Δ°S = -367 J/K

T = 25 C = 298.15 K

`\Delta G^(o)=-829000 J - (298.15 K* -367 J/K) = -719,578.95 J`

`X(s)\rightarrow X^(2+)(aq)+2e^-`

`2Y^++2e^-(aq)\rightarrow 2Y(s)`

n = 2

`-719,578.95 J=-2* 96500 C* E^o_(cell)`

`E^o_(cell)=(-719,578.95 J)/(-2* 96500 C)=3.73 V`

The standard cell potential at 25 ∘C for the reaction is 2.72 Volts.