# Which among the following statements are connect with respect to adsorption of gases on a solid ?$\; \;$ (1) The extent of adsorption is equal to $\;kp^{n}\;$ according to freundlich isotherm.$\;\;$ (2) The extent of adsorption is equal to $\;kp^{\large\frac{1}{n}}\;$ according to freundlich isotherm . $\;\;$ (3) The extent of adsorption is equal to $\;\large\frac{(a+bp)}{ap}\;$ according to freundlich isotherm . $\;\;$ (4) The extent of adsorption is equal to $\;\large\frac{ap}{(1+bp)}\;$ according to freundlich isotherm . $\;\quad\;$ (5) Freundlich adsorption fails at a low pressure .
$(a)\;1\;and\;3\qquad(b)\;1\;and\;4\qquad(c)\;2\;and\;3\qquad(d)\;2\;and\;4$