华南理工大学：《物理化学》课程教学课件（PPT讲稿）Chapter 4 Multi-component Systems

4.2 Expressions of concentration 2. molality mB def n B B The molality mB of a solute B is defined as the amount of substance of solute per unit mass of solvent The relationship between the mole fraction and the molality can be obtained from the definition of mole fraction 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 4.2 Expressions of concentration 2. molality mB B B A def n m m The molality mB of a solute B is defined as the amount of substance of solute per unit mass of solvent. The relationship between the mole fraction and the molality can be obtained from the definition of mole fraction

4.2 Expressions of concentration 3. molarity cB, or concentration of B def B amount-of-substance B where v is the volume of the solution, usually in cubic decimeters 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 4.2 Expressions of concentration 3. molarity cB , or concentration of B B def B n c V amount - of - substance where V is the volume of the solution, usually in cubic decimeters

4.2 Expressions of concentration B mass fraction of B B B The ratio of mass of solute to the total mass of solute and solvent 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 4.2 Expressions of concentration 4. wB mass fraction of B ( ) B B m 总 m w = The ratio of mass of solute to the total mass of solute and solvent

The important relations Z=ZO, w) w=w(x, y) aZ OZ dz=( a%dx+()ch;=(如)+() aZ OZ、,Ow Ow (=)dx+(-)n[(x),dx+()dy dx X OZ OZ、Ow OZ、Ow )u dx+o ),Cx+()2()dy OX 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 The important relations Z = Z(x,W ) W =W (x, y) dw w Z dx x Z dZ w x ( ) ( )   +   = dy y w dx x w dw y x ( ) ( )   +   = ( ) ( ) [( ) ( ) dy] y w dx x w w Z dx x Z w w y x   +     +   = dy y w w Z dx x w w Z dx x Z w x y x x ( ) ( ) ( ) ( ) ( )     +     +   = ;

The chain relation z=Z(x,y)dz=(0),a+(0)y OX By comparing with the coefficients of dx and dy in two dzs egs gives aZ OZ、O1w O OZ OZ OZ、O1w OX 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 chain relation Z = Z(x, y) dy y Z dx x Z dZ y x ( ) ( )   +   = By comparing with the coefficients of dx and dy in two dZ’s eqs gives: x x x y w w Z y Z ( ) ( ) ( )     =   y w x y x w w Z x Z x Z ( ) ( ) ( ) ( )     +   =  