part 3-unit 1-lesson 4

Physical Chemistry looks at chemistry from a different angle to inorganic and organic chemistry. Whereas these branches study the reactions of different groups of elements and compounds, physical chemistry uses mathematics and physics to determine laws which describe the way chemical reaction happen.
are called endothermic（吸热的） and usually mean
that chemical bonds have been formed.
Atomic Structure
Quantum mechanics （量子力学）deals with the structure of the very foundational units （基本单位 ）of all matter, atoms. So the arrangement（排列） of atoms in different solids such as steel, concrete（ 混凝土） and ice are determined by this discipline（ 学科，规律，规则）. But this study also led to （ 引起，导致）the discovery of the structure of the atomic nucleus leading to （引起，导致） both the atomic bomb（原子弹） and nuclear energy（核能 ）.
Energy Changes
Thermodynamics involve changes in energy. Changes in heat energy cause changes in temperature, which is foundational to （基本的，基础的，重要的） cooking, refrigeration（制冷） and transport（运输 ）. Chemical reactions which produce heat are
Physical chemistry is a less glamorous（闪耀的） but foundational（基础的，重要的） part of scientific study
Phases or states of matter
Homework
1. Read the text thoroughly 2. Special terms of physical chemistry
Catalysts
The study of the way rates of reaction can be changed by catalysts （催化剂）like enzymes or precious metals （贵金属）such as platinum（铂 ） or rhodium（铑） is important. Reverse catalysts（反催化剂） or inhibitors（抑制剂） are important in the preservation （保存）of foodstuffs （食品）and have been greatly developed.
Energy, Structure and Rate
So physical chemistry deals with （涉及，处理）
Thermodynamics（热力学） or the energy levels and
changes involved in chemicals and chemical reactions. It also deals with the Quantum Mechanics （量子力学 ）of chemicals. This is the atomic and molecular structure of the chemicals. Finally it deals with Kinetics （动力学）or the rates of reactions and how they are changed.
Obscure but Fundamental
It could be argued that （可以说，有人说，可能） this is the least interesting of the branches of chemistry. It involves lots of mathematical formulae and obscure（难懂的） theories involving Greek letters. Of course these concepts are also vital for many important processes in nature and in many of the equipment we take for granted.
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Speed of Reaction
Kinetics（动力学） is about speed of reaction. We depend on （依赖）reaction rates in so many ways in our modern lives. If reactions in the body did not involve enzymes （酶）which control the rate of the reactions, we would not be able to live（活） due to the reactions happening too slowly. The different cooking methods demonstrate the way different conditions affect （影响）the rate of reaction; to bake （焙烤）a potato takes hours in a conventional oven（炉）, but only a matter of minutes（几分钟 的事情） in a microwave oven（微波炉）.
Unit 2/Lesson 4
Physical Cay
➢ Energy, Structure and Rate ➢ Obscure but Fundamental ➢ Energy Changes ➢ Atomic Structure ➢ Speed of Reaction ➢ Catalysts ➢ Collision Theory
Accuracy precision Selectivity sensitivity standard deviation reagent Gross/Absolute/relative
error standardization Systematic/random error significant figure background
exothermic（放热的）, such as in burning fuel or an
exploding bomb（爆炸性的炸弹）. This usually means that chemical bonds have been broken. Chemical reactions which take heat in （拿取热量）
Collision Theory
The way conditions affect reaction rates is all about collisions（碰撞）. For example as temperature increases the particles（粒子） move around faster and so are more likely to collide（碰撞） and react quicker. Higher concentration also causes more collisions. This is an important part of the study of kinetics.
化学化工专业英语
Specialty English for Chemistry and Chemical Engineering
主讲 丁明洁 河南城建学化工学院
小测试
assay titration primary standard Internal/external standard matrix analyte reagent indicator interference stoichiometric point masking equivalent point purity / impurity