The following Gibbs energy data apply at 1 bar and 25degree C Determine the stan

Question

The following Gibbs energy data apply at 1 bar and 25degree C Determine the standard Gibbs energy change and the equilibrium constant for the following reactions, using the data given above: A solution contains initially. Is it an equilibrium solution? Assume all activity coefficients are unity. If not, what is the Gibbs energy of reaction for the formation of more AgCI(s) under these conditions? What reaction will occur spontaneously? Find the concentrations of all the species, including the solid, when equilibrium is attained.

Explanation / Answer

ai)

AgBr(s) --> Ag+ + Br-

G = 77.12 +-104 - (-96.90) = 70.02

aii)

PO4-3 + H+ --> HPO4-2

G = -1130.4 - (-1089.3 + 0) = -41.1

aiii)

HPO4-3 + H+ --> H2PO4-2

G = -1130.4 - (-1089.3-0) = -41.1

aiv)

PO4.3 + 2H --> H2PO4-2

G = -1130.4 -(-1018.8 + 0) = -111.6 kJ/mol

av)

AgBr + Cl- --> AgCl + Br-

G = -109.8 + -104 - (-96.9 + -131.3) = 14.4

b)

this must be in equilibrium, since there is solid AgCl

c)

Ksp = [Ag+][Cl-]

Ksp = 1.8*10^-10

Ag+ = 10^-5 + x

Cl- = 10^-2 + x

AgCl = 10^-6 - x = 1

then

Ksp = [Ag+][Cl-]

1.8*10^-10 = (10^-5 + x)(10^-2 + x)

from here, the smallest number is the one of Ag+ so

[Cl-] is not limited

solve for x

1.8*10^-10 = (10^-5 + x)(10^-2 + x)

0 = - 1.8*10^-10 + (10^-5)(10^-2) * (10^-2 +10^-5)*x + x^2

x = 9.8*10^-6

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---