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Consider the following reaction:

I_{2}(g) + Cl_{2}(g) ⇌ 2ICl(g) *K*_{p}= 81.9 at 25 ∘ C.

Calculate Δ*G ^{o}*rxn for the reaction at 25

^{o}C under each of the following conditions.

**Part A:** Standard conditions

**Part B:** At equilibrium

**Part C:**

*P*ICl= 2.59 atm

*P*I_{2}= 0.322 atm

*P*Cl_{2}= 0.221 atm

**Free Energy**

The Gibbs free energies and the equilibrium constant in relation to the pressure or concentration for the particular species when at particular temperature are correlated to one another according to the equation below. Any undetermined value can be discovered in the event that the other equation parameters are established.

Concepts and ReasonThis is the reaction:

I

_{2}(g) + Cl_{2}(g) ⇌ 2ICl(g)Use the following formula to calculate the Gibbs-free energy change for the reaction.

ΔG

_{rxn }= ΔG^{o}+ RT lnQHere, ΔG

^{o}^{ }is Gibbs free energy change in standard conditions, R gas constant, T is temperature, and Q is reaction quotient.Calculate ΔG

^{o }by using the following formula.ΔG

^{o }= -RT lnKHere K is the equilibrium constant for the reaction.

Below, calculate the reaction quotient.

FundamentalsStandard free energy change is the change in Gibbs free energy when one mole is made from its pure elements under normal conditions. Standard conditions are 1atm temperature and 298K temperatures.

At equilibrium, Gibbs free energy for a reaction will equal zero.

A)ΔG

^{o }= -RT lnK_{p}ΔG

^{o }= -8.314 J/mol.K x 298K x ln(81.9)= -8.314 J/mol.K x 298 x 4.405

= -10913 J/mol

= -10.91 kJ/mol

-10.91 kJ/mol is therefore standard Gibbs energy change free.

B)At equilibriumGibbs free energy change is zero.

ΔG

^{o }^{ }= 0(C)Answer:Part A:

Standard Gibbs energy change is -10.91 kJ/mol.

Part B:

ΔG

^{o }^{ }= 0Part C:

ΔG

_{rxn}^{ }^{ }= 0.353 kJ/mol