You are interested in finding the pressure at which the first bubble of vapor will form from a liquid mixture of ethanol (1) and benzene (2) (49% by mole ethanol) at 313 K. The Margules parameters for this mixture are A_{12 =} 2.173 and A₂₁ = 1.539, while the Wilson parameters for this mixture are a₁₂/R = 653.13 K and a₂₁/R = 66.16 K. Find the pressure and vapor-phase composition using three ways. 

A. The 2-parameter Margules equation 

B. The Wilson equation 

C. Ideal solution