For an ideal solution of two components A and B, If xA and yA are mole fractions of component 'A' in solution and vapour phase respectively, then the slope of linear line in the graph drawn between 1/xA and 1/yA is

According to raoult,s law ;  Where ;   = VP of pure A        ;           = VP of pure B             XA= M.F of A  in liquid phase    ;    YA= M.F of  A  in vapour phase             XB= M.F of B  in liquid phase      ;     YB= M.F of  B  in vapour phase                In vapour phase , according to Dalton's lawit is in the form y=mx+cIn the graph between 1/XA   &    1/YA