时差N小时 为什么盐能加速冰融化?(上)

Why does salt melt ice?

为什么食盐能让冰块融化?

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。

Oh, OK. Wait, I don't get it. Doesn't 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?

Let me explain. Pure water freezes at thirty-two degrees Fahrenheit¹, right?

我解释一下。纯净水的冰点是32华氏度，对吧?

At that temperature we can say that the rate of freezing is the same as the rate of melting.

这个温度既是冰点也是熔点。

So in other words, at water's freezing point there's a sort of equilibrium² between freezing and melting.

也就是说，水的冰点就是结冰和融化的平衡。

Right. Throwing salt on ice upsets the balance.

是的。在冰上洒盐扰乱了这种平衡。

Upsets it how?

怎么打乱的呢?

The salt dissolves into the liquid water, which means that some of the water molecules³ are replaced by salt.

盐溶解在水中，就是说一部分水分子被盐取代了。

1 Fahrenheit   

n./adj.华氏温度；华氏温度计(的)

参考例句：

• He was asked for the boiling point of water in Fahrenheit.他被问到水的沸点是华氏多少度。
• The thermometer reads 80 degrees Fahrenheit.寒暑表指出华氏80度。

2 equilibrium   

n.平衡，均衡，相称，均势，平静

参考例句：

• Change in the world around us disturbs our inner equilibrium.我们周围世界的变化扰乱了我们内心的平静。
• This is best expressed in the form of an equilibrium constant.这最好用平衡常数的形式来表示。

3 molecules   

分子( molecule的名词复数 )

参考例句：

• The structure of molecules can be seen under an electron microscope. 分子的结构可在电子显微镜下观察到。
• Inside the reactor the large molecules are cracked into smaller molecules. 在反应堆里，大分子裂变为小分子。