What is the best description of an azeotropic mixture? a liquid mixture containing two or more substances that boils at a constant characteristic temperature lower or higher than any of its components and that retains the same composition in the vapor state as in the liquid state. a liquid mixture of two or more substances that boils at a different characteristic temperature. a liquid mixture of two or more substances that boils at a constant characteristic pressure. a liquid mixture of two or more substances that boils at a constant characteristic temperature and pressure