Question

1. Consider this thermodynamic data: ΔG_f⁰ I₂ (s) = 0 and ΔG_f⁰ I₂ (g) = 19.4 kJ/mol. Calculate ΔG_rxn⁰ for this reaction at 298K:

I₂(s) → I₂ (g)

Calculate the equilibrium constant K_p, at 298K,

Calculate the partial pressure of gaseous iodine at equilibrium at 298K

2. What is the pH and pOH of the following solution? Is the mixture acidic, basic, or neutral?
[H⁺] = 0.008M

3. What is the pH and pOH of the following solution? Is the mixture acidic, basic, or neutral?
[H⁺] = 0.00365M

4. What is the pH and pOH of the following solution? Is the mixture acidic, basic, or neutral?
[H⁺] = 0.00365M

5. What is the [H⁺], [OH^-] concentration in the following solution?
pH = -1.06

Answer 1

1) G^orxn is given by the difference in standard Gibbs Free Energy of Formation of the products to that of the reactants .

G^orxn = G^of productst - G^of reactan

G^orxn = 19.4 kJ/mol - 0

G^orxn = 19.4 kJ/mol

G = -RTlnKp
Kp = e^((-G)/(RT))

Kp = e ^{-19400/8.314 x 298}

Kp = e ^-7.83

Kp = 3.975 x 10^-4

I₂(s) I₂(g)

In the expression of Kp we leave out the solids

Kp = P_I2(g)

3.975 x 10^-4 = P_I2(g)