Given the following data, what is the value of delta Gf (in kJ) for N2O4 (g) at 25C.

N2O4(g)-----2NO2(g) Keq= 0.144
delta Gf: ? 51.30

I thought of using the equation:
delta G-RTlnQ

I am not sure if that's what I should use to find N2O4 though????

Choose one answer.

a. 46.40
b. -4.80
c. 102.60
d. 97.80
e. 107.40

I think this is what you want to do.

delta Gorxn = -RT*ln K
Solve for delta Gorxn. I get something like 4.8 kJ/mol but you need to confirm that.
Then DGorxn = (DGproducts)-(DGreactants)
4.8 = (2*NO2)-(N2O4)
4.8 = (2*51.3)-(N2O4)
(I look up the value of 51.3 for NO2.)
Solve for N2O4. I get something like 98 kJ/mol but check my work closely, especially for signs. I used 8.314 for R.

To find the value of delta Gf (Gibbs free energy change of formation) for N2O4 (g) at 25°C, you can use the equation:

delta G = -RT ln(Keq)

where delta G is the standard Gibbs free energy change, R is the gas constant (8.314 J/mol·K), T is the temperature in Kelvin (25°C = 298 K), and Keq is the equilibrium constant (0.144).

First, convert the temperature to Kelvin:

T = 25°C + 273.15 = 298 K

Now, substitute the values into the equation:

delta G = - (8.314 J/mol·K) × 298 K × ln(0.144)

Simplifying the equation:

delta G = - 2464.27 J/mol × ln(0.144)

Finally, convert the units from Joules to kilojoules (kJ) by dividing by 1000:

delta G = - 2.46427 kJ/mol × ln(0.144)

Calculating the value:

delta G ≈ -2.46427 kJ/mol × (-1.9365)

delta G ≈ 4.76944 kJ/mol

Therefore, the value of delta Gf for N2O4 (g) at 25°C is approximately 4.76944 kJ/mol.

Therefore, the correct answer is:

b. -4.80 (rounded to two decimal places)

To find the value of delta Gf (standard Gibbs free energy of formation) for N2O4(g) at 25°C, you can use the equation:

delta Gf = -RT ln(Keq)

where delta Gf is the value you are trying to find, R is the gas constant (8.314 J/mol·K), T is the temperature in Kelvin (25°C + 273.15 = 298.15 K), and Keq is the equilibrium constant (0.144).

Before calculating delta Gf, let's convert the equilibrium constant from units of concentrations to units of pressure. Since the given equilibrium expression mentions gases, it is more appropriate to use the partial pressure form:

Keq = (P(NO2))^2 / P(N2O4)

Now, you need to rearrange the equation to solve for P(N2O4):

P(N2O4) = (P(NO2))^2 / Keq

Next, substitute the given values P(NO2) = 1 atm (since there are no specific partial pressures provided) and Keq = 0.144 into the equation:

P(N2O4) = (1)^2 / 0.144 = 6.944 atm

Now, you have the partial pressure of N2O4, so you can calculate delta Gf:

delta Gf = -RT ln(P(N2O4))

Using the values R = 8.314 J/mol·K, T = 298.15 K, and P(N2O4) = 6.944 atm:

delta Gf = -(8.314 J/mol·K)(298.15 K) ln(6.944) ≈ -4.80 kJ/mol

Therefore, the correct answer is b. -4.80 kJ.