Chemistry Class

Question

Create an equilibrium expression for the following equation: C12H26 (g) + O2 (g) ⇌ H2O (g) + CO2 (g)

Answer 1

When we make K_eq equations we ignore liquids and solids, only gases and aqueous solutions are considered because their concentrations can change. Since all the substances in the equation are gasses, all of them will be accounted for in our K_eq equation. All we have to do is put the products over the reactants and put the coefficients in front of each as their exponents. Of course in order to do that we must first balance our equation so we know what the coefficients will be.

Initial Equation:

C₁₂H₂₆ (g) + O₂ (g) ⇌ H₂O (g) + CO₂ (g)

Balanced Chemical Equation:

2C₁₂H₂₆ (g) + 37O₂ (g) ⇌ 26H₂O (g) + 24CO₂ (g)

As a result, our K_eq is:

K_eq = [H₂O]²⁶ [CO₂]²⁴ / [C₁₂H₂₆]² [O₂]³⁷