华南理工大学：《物理化学》课程教学课件（PPT讲稿）第三章 热力学第二定律 The second law of thermodynamics（上）

物理化学电子教案第三章(上) 热学能巴 不可能把热从低温 物体传到高温物体 而不引起其它变化 The Secons as of hiearmmodsymatmics 4上一内容下一内容令回主目录 返回 2021/2/21

上一内容 下一内容 回主目录 返回 2021/2/21 不可能把热从低温 物体传到高温物体， 而不引起其它变化 物理化学电子教案—第三章（上）

Chapter 3 The second law of thermodynamics 3.1 Common feature of spontaneous change 3.2 The second law of thermodynamics 3. 3 Carnot cycle and Carnot principle 3.4 Definition of entropy 3.5 Clausius inequality principle of increase of entropy 3.6 Calculate the change of entropy 3.7 Statistical view of entropy 4上一内容下一内容◇回主目录 返回 2021/2/21

上一内容 下一内容 回主目录 返回 2021/2/21 Chapter 3 The second law of thermodynamics 3.1 Common feature of spontaneous change 3.2 The second law of thermodynamics 3.3 Carnot cycle and Carnot principle 3.4 Definition of entropy 3.5 Clausius inequality ; principle of increase of entropy 3.6 Calculate the change of entropy 3.7 Statistical view of entropy

The second law of thermodynamics 3. 8 Helmholtz function and gibbs function 3.9 Direction of change and conditions in equilibrium 3.10 Calculate of△G 3.11 Relations of thermod ynamic functions 3.12 Clapeyron equation 3. 13 The third law and conventional entropy 4上一内容下一内容◇回主目录 返回 2021/2/21

上一内容 下一内容 回主目录 返回 2021/2/21 The second law of thermodynamics 3.9 Direction of change and conditions in equilibrium 3.10 Calculate of G 3.11 Relations of thermodynamic functions 3.12 Clapeyron equation 3.13 The third law and conventional entropy 3.8 Helmholtz function and Gibbs function

3.1 Common feature Spontaneous change Some things happen spontaneously, some things don t Common feature --irreversible A gas expands to fill the available volume it does not spontaneously contract into something smaller a hot body cools to the temperature of its surroundings, it does not spontaneously get hotter at their expense 4上一内容下一内容令回主目录 返回 2021/221

上一内容 下一内容 回主目录 返回 2021/2/21 3.1 Common feature Spontaneous change :Some things happen spontaneously, some things don`t. Common feature —irreversible A gas expands to fill the available volume; it does not spontaneously contract into something smaller. A hot body cools to the temperature of its surroundings;it does not spontaneously get hotter at their expense

What determines the direction of...? Can the direction of the spontaneous change be related to some aspect of the distribution of energy? We shall see that this is so. Spontaneous changes are always accompanied by a reduction in the quality' of energy, in the sense that it is degraded into a more dispersed, chaotic form Spontaneous, natural changes are simply manifestation of the natural tendency of the universe towards greater chaos 4上一内容下一内容令回主目录 返回 2021/221

上一内容 下一内容 回主目录 返回 2021/2/21 What determines the direction of …? Can the direction of the spontaneous change be related to some aspect of the distribution of energy? We shall see that this is so. Spontaneous changes are always accompanied by a reduction in the ‘quality’ of energy,in the sense that it is degraded into a more dispersed, chaotic form. Spontaneous, natural changes are simply manifestation of the natural tendency of the universe towards greater chaos

3.2 The Second Law of Thermodynamics Clausius statement:it is impossible for any device to operate in a cycle in such a manner that the sole effect is the transfer of heat frol body at a higher temperature h one body to another Kelvin-Planck statement:"no process is possible whose sole result is the absorption of heat from a reservoir and the conversion of this heat into work The second perpetual motion machine is no way 4上一内容下一内容令回主目录 返回 2021/221

上一内容 下一内容 回主目录 返回 2021/2/21 3.2 The Second Law of Thermodynamics Clausius statement： “it is impossible for any device to operate in a cycle in such a manner that the sole effect is the transfer of heat from one body to another body at a higher temperature.” Kelvin-Planck statement： “no process is possible whose sole result is the absorption of heat from a reservoir and the conversion of this heat into work.” The second perpetual motion machine is no way!

Measuring dispersal. the entropy The first law led to the introduction of the internal energy, a property of state. The Second Law also leads to a property, the entropy. The First law uses the internal energy to identify the permissible changes, the Second law uses the entropy to identify the natural changes among these permissible changes 4上一内容下一内容令回主目录 返回 2021/2/21

上一内容 下一内容 回主目录 返回 2021/2/21 Measuring dispersal : the entropy The First Law led to the introduction of the internal energy, a property of state. The Second Law also leads to a property, the entropy. The First Law uses the internal energy to identify the permissible changes; the Second Law uses the entropy to identify the natural changes among these permissible changes

The statistical view of the entropy One way of introducing the entropy develops the view that the extent of the dispersal of energy can be calculated this leads to the statistical definition of entropy. Another develops the view that the dispersal can be related to the amount of heat involved in a process: this leads to the thermodynamic definition 4上一内容下一内容◇回主目录 返回 2021/2/21

上一内容 下一内容 回主目录 返回 2021/2/21 The statistical view of the entropy One way of introducing the entropy develops the view that the extent of the dispersal of energy can be calculated: this leads to the statistical definition of entropy. Another develops the view that the dispersal can be related to the amount of heat involved in a process: this leads to the thermodynamic definition

Carnot Cycle Of particular interest is an 高温存储器 idealized engine, known as On the Carnot engine, which employs two heat 热机 reservoirs at different temperatures and operates on the following cycle 低温存储器 卡诺循环 4上一内容下一内容◇回主目录 返回 2021/2/21

上一内容 下一内容 回主目录 返回 2021/2/21 Carnot Cycle Of particular interest is an idealized engine, known as the Carnot engine, which employs two heat reservoirs at different temperatures and operates on the following cycle

Carnot cycle Process 1: A reversible isothermal expansion at Th Process 2. A reversible adiabatic expansion A(p1 V1) Process 3 A reversible isothermal B(lava compression at T2 D(p4 V4 C(p3 Vs) Process 4: A reversible adiabatic compression 卡诺循环 4上一内容下一内容令回主目录 返回 2021/2/21

上一内容 下一内容 回主目录 返回 2021/2/21 Carnot cycle Process 4: A reversible adiabatic compression Process 3: A reversible isothermal compression at T2 Process 2: A reversible adiabatic expansion. Process 1: A reversible isothermal expansion at Th