Question

At what temperature, Teq, do the forward and reverse corrosion reactions occur in equilibrium?

Answer 1

Answer:

See explanation below.

Explanation:

We can obtain the Gibb's free energy from the formula;

∆G= ∆H - T∆S

Where;

∆G = change in free energy= the unknown

∆H= change in enthalpy = 3352 kJ

∆S= change in entropy of the solution= 625.1 J/K

T= absolute temperature = 298 K

Substituting values;

∆G= 3352 ×10^3 J - (298 K × 625.1 J/K)

∆G= 3352 ×10^3 J - 186279.8

∆G= 3.16 × 10^6 J

At 5975K,

∆G= ∆H - T∆S

∆G= 3352 ×10^3 J - (5975K × 625.1 J/K)

∆G= 3.352 ×10^6 J - 3.735 × 10^6

∆G= -3.83×10^5 J

At equilibrium, ∆G=0, Teq is given by;

0= 3352 ×10^3 J - (Teq × 625.1 J/K)

0= 3352 ×10^3 - 625.1Teq

625.1Teq = 3352 ×10^3

Teq= 3352 ×10^3/625.1

Teq= 5362.3 K