chapter2第二章物质的状态.ppt

第二章 物质的状态 chapter 2 state of matter 1 气体　(gas) 2 液体　(liquid) 3 固体　(solid) § 2-1 gas 1—1 理想气体 (ideal gas, or perfect gas)重点讲解 Definition of ideal gas 气体分子只有质量而没有体积 气体分子之间没有相互吸引力 气体分子之间及分子与器壁之间发生的碰撞不造成动能损失 Which kind of gas can be thought as quasi-ideal gas? Real gas, or imperfect gas Temperature : high　　the distance among molecules : far volume ignored Pressure: low interaction among molecules: weaker ignored （1）理想气体的状态方程式ideal gas law equation 波义尔定律：当n和T一定时，气体的V与p成反比 V ∝1/p （1） 查理-盖吕萨克定律： n和p一定时，V与T成正比 V ∝T （2） 阿佛加德罗定律：p与T一定时，V和n成正比 V ∝n （3） 以上三个经验定律的表达式合并得V ∝ nT/p (4) 实验测得（4）的比例系数是R，于是得到 pV=nRT (5) 这就是理想气体状态方程式 pV=nRT International System of Units : p: Pa Pascal 帕，v: m3 立方米 ， T : K 开尔文， Gas constant: R:8.314 J·mol-1·K-1 From the gas equation: Derive the ideal gas equation Example 2-1、example 2-2 page 18 Example 2-3, page 18 设计实验 Partial volume Partial volume About law of partial pressure law of gas diffusion Example 2-7, 2-8 page 22 Application: separate the raw material of atomic bombU235 from the mixture of U235 and U238 Vapor pressure and  Temperature See page 35, table 2-7 and table 2-8 (3) Evaporation heat From the Clansius-Clapeyron equation 1) calculate the evaporation heat during the procedure from T1 to T2 2) calculate the vapor pressure at some temperature 2-2 boiling point boiling point : abbr. bp The temperature at which a liquid boils at a fixed pressure, especially under standard atmospheric conditions. (1) at the boiling point: i) vapor pressure=external pressure ii) evaporation happened through the whole liquid (2) before the boiling point: i) vapor pressure less than external pressure ii) evapora