Entropy, Free Energy and Equilibrium

[Hockeystar]

Homework Statement

The enthalpies and Gibbs energies of formation of the metal oxide Ag₂O are:

deltaH⁰_f = -31.05 KJ/mol
deltaG⁰_f = -11.20 KJ/mol

Determine to what temperature must it be heated to produce O₂(g) at 1.00 atm pressure?

Homework Equations

deltaG⁰_f = -RTln(k)

K = PO₂^0.5

The Attempt at a Solution

NVM solved it

 

[nate808]

Hi there,

To determine the temperature at which Ag2O will produce O2(g) at 1.00 atm pressure, we can use the equation:

deltaG0f = -RTln(k)

Where:
deltaG0f = Gibbs energy of formation of Ag2O
R = gas constant (8.314 J/mol*K)
T = temperature (in Kelvin)
k = equilibrium constant for the reaction

First, we need to find the equilibrium constant (k) for the reaction:

2Ag2O(s) --> 4Ag(s) + O2(g)

We can use the equation:

K = PO20.5

Where:
P = partial pressure of O2(g)
O = standard state pressure (1.00 atm)

Since we want to produce O2(g) at 1.00 atm pressure, we can substitute these values into the equation:

K = (1.00)^0.5 = 1

Now, we can plug this value into the original equation:

deltaG0f = -RTln(k)

-11.20 KJ/mol = -8.314 J/mol*K * T * ln(1)

Solving for T, we get:

T = -11.20 KJ/mol / (-8.314 J/mol*K) = 1346 K

Therefore, the temperature at which Ag2O will produce O2(g) at 1.00 atm pressure is 1346 Kelvin.

I hope this helps! Let me know if you have any further questions.