一、商品的概念及特点 (一)商品的概念 1、一般概念 商品是人类社会生产力发展到一定历史阶段 的产物,它是为了交换或出卖而生产的劳动产品 。商品具有使用价值和价值两种属性,是使用价 值和交换价值的统一体

程序设计是一项实践性很强的工作, 掌握程序设计的方法,不仅需要有解决问 题的算法和程序设计语言的语法知识,更 需要勤于动手、动脑去编程和上机实践。 就如同学游泳一样,在陆地上是永远学不 会游泳的。程序设计的最终目的是让计算 机去完成人们的意愿,实现人与计算机之 间的沟通。最终是否能达到这一目标,还 必须要在计算机上运行该程序,以检验它 的正确性

Wave Properties of Electrons Standing wave vibrates in fixed location. Wave function, w, mathematical description of size, shape, orientation Amplitude may be positive or negative Node: amplitude is zero

To determine reaction''s mechanism, look at: Equilibrium constant Free energy change Enthalpy Entropy Bond dissociation energy Kinetics >Activation energy

Classes of Halides Alkyl: Halogen, X, is directly bonded to sp3 carbon. Vinyl: X is bonded to sp2 carbon of alkene. Aryl: is bonded to sp2 carbon on benzene ring. Examples:

Reactivity of C=C C—C Electrons in pi bond are loosely held Electrophiles are attracted to the pi electrons. · Carbocation intermediate forms. Nucleophile adds to the carbocation. · Net result is addition to the double bond

Classification Primary: carbon with -OH is bonded to one other carbon. Secondary: carbon with-OH is bonded to two other carbons. · Tertiary: carbon with-OH is bonded to three other carbons. Aromatic(phenol): -OH is bonded to a benzene ring

Spectroscopy is an analytical technique which helps determine structure. It destroys little or no sample. The amount of light absorbed by the sample is measured as wavelength is varied

Introduction Formula R-O-R where R is alkyl or aryl. Symmetrical or unsymmetrical Examples:

Discovery of Benzene Isolated in 1825 by Michael Faraday who determined C: H ratio to be 1: 1. Synthesized in 1834 by Eilhard Mitscherlich who determined molecular formula to be C6H6