${K_p}\,\, = \,\,\frac{{{x^2}p}}{{1\,\, - \,\,{x^2}}}\,\, = \,\,\frac{{\sqrt {0.5} \,\, \times \,\,\sqrt {0.5} \,\, \times \,\,p}}{{1\,\, - \,\,\sqrt {0.5} \,\, \times \,\,\sqrt {0.5} }}\,\, = \,\,\frac{{0.5\,\, \times \,\,p}}{{1\,\, - \,\,0.5}}\,\, = \,\,p$