Question

Methanol. The change in standard free energy for the synthesis of liquid methanol from gaseous carbon monoxide and hydrogen is -29 kJ/mole of methanol. Write the balanced reaction equation, the equilibrium constant expression?

This involves Gibbs Free Energy but I do not know how to solve this.

Answer 1

Here's what I get.

Explanation:

The balanced equation

`"CO(g) + 2H"_2"(g)" → "CH"_3"OH(l)"; Δ_text(r)G^@ = "-29 kJ·mol"^"-1"`

The equilibrium constant expression

`K_text(p) = 1/(p_text(CO)p_text(H₂)^2)`

The equilibrium constant

`ΔG^@ = "-"RTlnK`

`lnK = -(ΔG^@)/(RT) = -("-29 000" color(red)(cancel(color(black)("J.mol"^"-1"))) )/(8.314 color(red)(cancel(color(black)("J·K"^"-1""mol"^"-1"))) × 298 color(red)(cancel(color(black)("K")))) = 11.7`

`k = e^11.7 = 1.2 × 10^5`