The reaction A_2 (g) + B_2 (g) 2 AB(g) has an equilibrium constant K = 1 at 25 d

Question

The reaction A_2 (g) + B_2 (g) 2 AB(g) has an equilibrium constant K = 1 at 25 degree C. The following diagrams represent reaction mixtures containing A_2 molecules, B_2 molecules, and AB molecules. You will need to determine the value of the reaction quotient Q for each mixture. (a) Determine the value of Delta G (Delta G = 0, Delta G = 0, or AG > 0) for each reaction mixture. Justify your reasoning. (b) Use your results from part (a) and determine for each reaction mixture whether it is at equilibrium, is spontaneous, or is nonspontaneous. Justify your reasoning.

Explanation / Answer

A2 (g) + B2 (g) = 2 AB (g)

Calculation of reaction quotient in three different mixtures:-

Mixture (1)

Number of molecules of A2 = 1, B2 = 1 and AB = 7

Q = [AB]2 / [A2][B2] = (7)2 / 1*1 = 49

Mixture (2)

Number of molecules of A2 = 4, B2 = 4 and AB = 1

Q = [AB]2 / [A2][B2] = (1)2 / 4*4 = 0.0625

Mixture (3)

Number of molecules of A2 = 3, B2 = 3 and AB = 3

Q = [AB]2 / [A2][B2] = (3)2 / 3*3 = 1

(a) & (b)

DeltaG0 = - R T lnQ

For mixture (1)

deltaG0 = - 0.008314 * 298 * ln(49) = - 9.64 kJ

deltaG0 < 0, spontaneous

For mixture (2)

deltaG0 = - 0.008314 * 298 * ln(0.0625) = + 6.87

deltaG0 > 0, not spontaneous

For mixture (3)

deltaG0 = - 0.008314 * 298 * ln(0) = 0

deltaG0 = 0 , the reaction is at equilibrium

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.