The reaction H2(g) + CO2(g) \(\rightleftharpoons\) CO(g) + H2O(g) has initial concentration of [H2] = [CO2] = 1 mol/L and x mol/L of hydrogen is consumed at equilibrium, the correct expression for Kc is
1
\(\frac{{{x^2}}}{{1 - {x^3}}}\)
2
\(\frac{{{x^2}}}{{{{\left( {1 - x} \right)}^2}}}\)
3
\(\frac{{{x^2}}}{{{{\left( {2 - x} \right)}^2}}}\)
4
\(\frac{{{x^2}}}{{{{\left( {2 + x} \right)}^2}}}\)