A liquid mixture of two or more substances that retains the same composition in the vapor state as in the liquid state when distilled or partially evaporated under a certain pressure.

• 共沸混合物两种或多种物质组成的液体混合物，当在某种压力下被蒸馏或局部汽化时，在气体状态下和在液体状态下保留相同的物质的成分