当瘦母牛吃掉肥母牛 ——论热力化学（When a lean cow eats a fat cow -- heat chemistry）.doc

当瘦母牛吃掉肥母牛 ——论热力化学（When a lean cow eats a fat cow -- heat chemistry） First, the concept of enthalpy People often encounter things make clear distinction between the two sides, either good or bad luck is not luck, not the light is dark, happiness is not sad, not success or failure...... Scientists also initially divided chemical reactions into endothermic reactions or exothermic reactions, but found that both endothermic and exothermic reactions were of great benefit to life on earth. Chemists in the nineteenth Century spent a lot of time thinking, what happens to chemical reactions? This problem. When the rolling stone, the driving force behind certain; when the apples fell from the tree, is affected by the gravity of the eagle in the sky fly high; Teng, by heat lift help; these phenomena have a common characteristic, is the obvious strength in promoting. But what is the chemical reaction driving force? If you dont know what kind of power in promoting, it cannot answer why chemical reaction will happen? The question has led to the theory of thermodynamics (thermodynamic). German chemist Ulrike (Hermann, Ullich, 1895-1945) proposed the concept of enthalpy (enthalpy) to explain the progress of chemical reactions. Since most of the chemical reactions are under certain air pressure or at a certain height, he defines enthalpy as the heat of the chemical reaction under certain air pressure. Based on the enthalpy, he found that some chemical reactions would release heat and raise the temperature around, which he called an exothermic reaction (exothermic). There are also reactions that absorb energy and reduce the temperature around, which he calls the endothermic reaction (endothermic). He suggested that the chemical reaction in nature would be exothermic if the outside world did not provide sufficient energy. Exothermic reactions are obvious, for example, burning gasoline is exothermic reaction, the car is only released by the heat of gasoline to drive the engine, to drive