There exist two liquid regions in these isothermal sections.One is the equilibrium region of a single liquid phase with solid hydroquinone.Another is a broad region of two partially miscible liquids.

• 这两个等温截面的特点是：存在单相液体与对苯二酚固体的平衡区域，同时存在液相分层的广阔的两相共存区域。