The Second Law of Thermodynamics Part I PDF文件使用"pdfFactory Pro”试用版本创建wm,fineprint.com,cn
1 The Second Law of Thermodynamics Part I PDF 文件使用 "pdfFactory Pro" 试用版本创建 Ìwww.fineprint.com.cn
Contents The direction of spontaneous change .Concentrating on the system .Combining the First and Second Laws .Properties of the Gibbs energy 2 PDF文件使用"pdfFactory Pro”试用版本创建m,fineprint.com,cn
2 Contents • The direction of spontaneous change •Concentrating on the system •Combining the First and Second Laws •Properties of the Gibbs energy PDF 文件使用 "pdfFactory Pro" 试用版本创建 ÿwww.fineprint.com.cn ÿ
The first law of thermodynamics states that when one form of energy is converted to another,the total energy is conserved.It does not indicate any other restriction on this process.However,we know that many processes have a natural direction,and it is with the question of direction that the second law is concerned. The purpose of this chapter is to explain in the origin of the spontaneity of physical and chemical change. PDF文件使用"pdfFactory Pro”试用版本创建www.fineprint.com.cn
3 The first law of thermodynamics states that when one form of energy is converted to another, the total energy is conserved. It does not indicate any other restriction on this process. However, we know that many processes have a natural direction, and it is with the question of direction that the second law is concerned. The purpose of this chapter is to explain in the origin of the spontaneity of physical and chemical change. PDF 文件使用 "pdfFactory Pro" 试用版本创建 www.fineprint.com.cn
Spontaneous processes Introduction occur without any outside intervention. Some processes in Nature are SPONTANEOUS. Other processes do not occur spontaneously and we have to force them to happen. e.g.,Place a hot body next to a cold body.The hot body transfers heat to the cold.We never observe the hot body getting hotter and the cold body getting colder! A book on a table can spontaneously fall to the floor. We never observe a book on the floor spontaneously arising! However,neither of these highly improbable events is forbidden by the First Law of Thermodynamics! PDF文件使用"pdfFactory Pro”试用版本创建iw,fineprint.com,c四
4 Introduction Some processes in Nature are SPONTANEOUS. Other processes do not occur spontaneously and we have to force them to happen. e.g., Place a hot body next to a cold body. The hot body transfers heat to the cold. We never observe the hot body getting hotter and the cold body getting colder! A book on a table can spontaneously fall to the floor. We never observe a book on the floor spontaneously arising! However, neither of these highly improbable events is forbidden by the First Law of Thermodynamics! Spontaneous processes occur without any outside intervention. PDF 文件使用 "pdfFactory Pro" 试用版本创建 Ìwww.fineprint.com.cn Ì
The First Law of Thermodynamics is really a statement of conservation of energy. system surroundings heat +Q work +w Change in internal energy heat added to system work done on system of a system from surroundings by surroundings △U=Q+w PDF文件使用"pdfFactory Pro”试用版本创建iw,fineprint.com.cn
5 The First Law of Thermodynamics is really a statement of conservation of energy. system surroundings heat +Q work +w Change in internal energy = heat added to system + work done on system of a system from surroundings by surroundings D U = Q + w PDF 文件使用 "pdfFactory Pro" 试用版本创建 Ìwww.fineprint.com.cn Ì