化学专业英语.ppt

Lesson 2 THE CLASSIFICATION OF INORGANIC COMPOUNDS无机化合物分类无机化合物分类chemist 化学家化学家equation 方程式方程式become 适合，与适合，与相称相称aqueous 水的水的radical 基，根，原子团基，根，原子团balance 天平，平衡天平，平衡acidic 酸的，酸性的酸的，酸性的substance 物质物质anhydride 酐酐sour 酸的，酸味的；变酸酸的，酸味的；变酸basic anhydride 碱酐碱酐taste 味道，气味，味觉味道，气味，味觉negative 负的，阴的负的，阴的lemon 柠檬柠檬acid radical 酸根酸根orange 柑，桔；橙色柑，桔；橙色share 共享，分享共享，分享citric 柠檬的柠檬的transfer 转移转移citric acid 柠檬酸柠檬酸 coordinate 配位配位 citrus 柑桔属柑桔属coordinate valence 配键配键lactic 乳的乳的hydronium ion 水合氢离子水合氢离子lactic acid 乳酸乳酸词汇词汇litmus 石蕊石蕊 soapy 肥皂般的，滑腻的肥皂般的，滑腻的 litmus paper 石蕊试纸石蕊试纸slippery 滑的滑的 dye 染料染料 neutralization 中和中和 soak 浸泡，浸渍浸泡，浸渍evaporation 蒸发蒸发 enable 使使能够能够 positive 正的，阳的正的，阳的 indicator 指示剂指示剂 positive ion 正离子正离子 methyl 甲基甲基 negative ion 负离子负离子 methyl orange 甲基橙甲基橙 lattice 格子，点阵格子，点阵 phenolphthalein 酚酞酚酞 crystal lattice 晶格晶格react (with, on) 反应反应 electrovalent 电价的电价的 strong acid 强酸强酸 orient 定向，取向定向，取向 ionize 离子化，电离离子化，电离 pattern 模型，形式模型，形式 bitter 苦味苦味 The Classes of Compounds 1.Thousands and tens of thousands of compounds are known to the chemist today. It would be impossible to learn properties and behavior of even a fraction of this number if it had to be done on the basis of individual compounds. Fortunately, most chemical compounds can be grouped together in a few classes. Then, if we can properly classify a compound, we are at once aware of the general properties of the compound from knowledge of the properties of that class or group of compounds. For example, HCl is classed as an acid, and by becoming familiar with the behavior of acids as a distinct class, we are at once aware of the general properties of the compound. A great many of the compounds we are to study may be classified as acids, bases, salts, metallic oxides, or nonmetallic oxides. Of these five classes of compounds, the first three-acids, bases, and salts-are by far the most important.The Classes of Compounds Thousands and tens of thousands of compounds are known to the chemist today. 化合物分类化合物分类现今，化学家知道了成千上万的化合物。现今，化学家知道了成千上万的化合物。 thousands and tens of thousands成千上万 be known to被所知chem(o) 化学（的） chemistry 化学 chemical 化学的，化学药品 chemosynthesis 化学合成 It would be impossible to learn properties and behavior of even a fraction of this number if it had to be done on the basis of individual compounds. 如果根据个别化合物来了解这么多化合如果根据个别化合物来了解这么多化合物的性质，即使其中的一小部分也是不可物的性质，即使其中的一小部分也是不可能的。能的。a fraction of 一小部分on the basis of 根据, 在基础上 Fortunately, most chemical compounds can be grouped together in a few classes. 幸运的是，大多数化合物能够组合在一起分成几类。幸运的是，大多数化合物能够组合在一起分成几类。 Then, if we can properly classify a compound, we are at once aware of the general properties of the compound from knowledge of the properties of that class or group of compounds. 那么，如果我们能够恰当地将一个化合物归类，我们立那么，如果我们能够恰当地将一个化合物归类，我们立刻就能从这类化合物的性质来了解这个化合物的一般性刻就能从这类化合物的性质来了解这个化合物的一般性质。质。 be aware of 知道，意识到 For example, HCl is classed as an acid, and by becoming familiar with the behavior of acids as a distinct class, we are at once aware of the general properties of the compound. become (be) familiar with熟悉，通晓例如，盐酸归类为酸，由于已熟悉作为不同类别例如，盐酸归类为酸，由于已熟悉作为不同类别的酸的性质，我们就会立即知道这一化合物的一的酸的性质，我们就会立即知道这一化合物的一般性质。般性质。 A great many of the compounds we are to study may be classified as acids, bases, salts, metallic oxides, or nonmetallic oxides. Of these five classes of compounds, the first three-acids, bases, and salts-are by far the most important. 我们将要研究的众多化合物可以分类为酸、碱、盐、我们将要研究的众多化合物可以分类为酸、碱、盐、金属氧化物或非金属氧化物。这五类化合物中的前三类金属氧化物或非金属氧化物。这五类化合物中的前三类酸、碱和盐是最重要的。酸、碱和盐是最重要的。 a great （good）many of 很多，大量 2. When an acid, base, or salt is dissolved in water the resulting solution is a conductor of the electric current and is termed an electrolyte. If no conduction of current occurs, the compound is known as a nonelectrolyte. 2. When an acid, base, or salt is dissolved in water the resulting solution is a conductor of the electric current and is termed an electrolyte. If no conduction of current occurs, the compound is known as a nonelectrolyte. 酸、碱或盐溶于水中得到的溶液是电流的导体，酸、碱或盐溶于水中得到的溶液是电流的导体，它们被定义为电解质。如果没有电流的传导发生，它们被定义为电解质。如果没有电流的传导发生，这种化合物被称为非电解质。这种化合物被称为非电解质。conductor 导体electric current 电流term 被称作electrolyte/nonelectrolyte 电解质，非电解质 3. Classification of Common Compounds By looking at the chemical formulas we may classify many common compounds in the following way. 1. Acids, in the conventional sense, may be recognized by noting that the H is written first in the formula and that the rest of the compound is generally nonmetallic. Ex., HCl, H2SO4, HClO. 2. Conventional bases have OH radicals written last in the formula. The first part of the formula is usually a metal. Ex., NaOH, Ca(OH)2, Fe(OH)3. 3. A salt consists of a metal, written first, combined with a non-metal or radical written last in a formula. Ex., NaCl, Fe2(SO4)3, Ca(ClO)2. 4. Oxides are compounds containing oxygen and only one other element. Classification of Common Compounds By looking at the chemical formulas we may classify many common compounds in the following way. 普通化合物分类普通化合物分类 我们可以根据化学式按着下面的方法分类许多普我们可