For the reaction
\(CO(g) + \frac{1}{2}{O_2}(g) \leftrightarrow C{O_2}(g)\)
\(\Delta {n_g} = 1 - \left( {1 + \frac{1}{2}} \right) = - \frac{1}{2}\)
\(\therefore \,{K_P} = \frac{{{K_C}}}{{\sqrt {RT} }};\,\frac{{{K_P}}}{{{K_C}}} = \frac{1}{{\sqrt {RT} }}\)