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Salt vs. Ice 食盐大战冰块 Y: Why does salt melt ice? 为什么食盐能让冰块融化? D: It lowers the melting and freezing point of water. 是因为食盐将水的熔点和冰点降低了。 Y: Oh,OK.Wait,I dont get it. Doesnt that mean the salt make ice colder? 等一下，我不明白。这就意味着食盐让冰的温度变得更低吗? D: Let me explain.Pure water freezes at thirty-two degrees Fahrenheit,right? At that temperature we can say that the rate of freezing is the same as the rate of melting. 我解释一下。纯净水的冰点是32华氏度，对吧?这个温度既是冰点也是熔点。 Y: So in other words, at waters freezing point theres a sort of equilibrium between freezing and melting. 也就是说，水的冰点就是结冰和融化的平衡。 D: Right.Throwing salt on ice upsets the balance. 是的。在冰上洒盐扰乱了这种平衡。 Y: Upsets it how? 怎么打乱的呢? D: The salt dissolves into the liquid water, which means that some of the water molecules are replaced by salt. Since there are now fewer liquid water molecules to be captured and frozen by the ice, the rate of freezing drops. | 
