Question

What is delta Gº for the following reaction at 25 °C?

CO(g) + 2 H2(g) = CH OH(9)
Ky = 2.1 x 10-4

Answer 1

21 kJ/mol

Step-by-step explanation:

Step 1: Given and required data

• Temperature (T): 25 °C (298 K)

• Equilibrium constant (Kc): 2.1 × 10⁻⁴

• Ideal gas constant (R): 8.314 J/K.mol

Step 2: Write the balanced equation at equilibrium

CO(g) + 2 H₂(g) ⇄ CH₃OH(g)

Step 3: Calculate the standard Gibbs free energy of the reaction (ΔG°)

We will use the following expression.

ΔG° = - R × T × ln Kc

ΔG° = - (8.314 J/K.mol) × 298 K × ln 2.1 × 10⁻⁴ = 2.1 × 10⁴ J/mol = 21 kJ/mol