Consider the decomposition of a metal oxide to its elements, where M represents

Question

Consider the decomposition of a metal oxide to its elements, where M represents a generic metal. Substance deltaG degree f(kJ/mol) M2O(s) -10.60 M(s) 0 O2(g) 0 What is the standard change in Gibbs energy for the reaction, as written, in the forward direction? delta G degree rxn = Number ____________ kJ / mol What is the equilibrium constant of this reaction, as written, in the forward direction at 298 K? K = Number _________________ What is the pressure of O2(g) over M(s) at 298 K? PO2 = Number _____________ atm

Explanation / Answer

A)

dG = Gproducts - Greactants

dG = 2*M + 1/2*O2 - (M2O)

dG = 2*0 + 1/2*0 - (-10.60)

dG = 10.60 kJ/mol

b)

For

dG = -RT*ln(K)

solve for K

K = exp(-dG/(RT))

substitute data, dG = 10.60 kJ/mol = 10600 J/mol, R = 8.314 J/molk; T = 298K

K = exp(-10600/(8.314*298))

K = 0.0138

c)

apply

K = 2*M * O2^1/2 / P-M2O

solids wont have partial pressure so

Kp = P-O2^0.5

0.0138 =  = P-O2^0.5

Solve for P-O2

P-O2 = (0.0138)^2

P-O2 = 0.00019044 atm

Related Questions

Navigate

• Browse (All)
• Browse C
• Subjects

---