The natural water content in hydrocarbon mixtures in a wide range of concentrations, temperature, and pressure conditions leads to important technological changes in the processes involved in the petroleum industry. For this reason, the physical understanding and mathematical modeling of these aqueous-organic mixtures constitutes a challenging task, both for scientists and for applied engineers. The present work focuses on the description of the phase behavior of binary mixtures of water (1) + n-alkane (2) [n= 1-36], considering the topological approach introduced by van Konynenburg and Scott. The phase behavior of the mixtures under analysis is predicted from a Carnahan Starling van der Waals equation of state with quadratic mixing rules, which is in qualitative agreement with experimental results. In terms of global transitional mechanisms, we describe the topological changes that systematically occur in the phase diagrams of water (1) + n-alkane (2) mixtures as the carbon number n of the aliphatic chain increases. These transitional mechanisms give coherence to the barotropic phenomena (phase density inversion) that is observed along the three-phase equilibrium line of water (1) + n-alkane (2) mixtures for n = 28-36.