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“化学通报”1957年1月号刊载张海若同志写的“我怎样教学生应用克分子的概念来做化学计算题”一文中,我以为其中有一个概念值得商榷,有一处错误必须更正。张海若同志认为“克分子是……重量单位”,他说“n代表物质以克分子为单位的重量”,并在0.2克分子CO_2与8.8克CO_2中间画上等号。这是不恰当的。“克分子”不是重量单位,它的物理意义是:①物质一定数目的分子,即6.02×10~(23)个分子,②它们的总重量若以克为单位来表示,则其数值恰等于其分子量。其物理量表示方法应该是M克/克分子(M表示分子量数值)。例如某物质0.2克分子重3.6克,其一克分子重: 3.6克÷0.2克分子=18克/克分子。张海若同志所举的两个例子,可作如下计算:
In the January 1957 issue of Chemical Bulletin, I read a commentary written by Comrade Zhang Hairuo on “How Can I Teach Students to Use Chemists’ Concepts to Do Chemical Calculations?” I think one of these concepts is open to question and one of them must be corrected. Comrade Zhang Haoruo held that “a molecule is ... a unit of weight.” He said “n represents the weight of a substance in moles” and equates among 0.2 grams of molecular CO2 and 8.8 grams of carbon dioxide. This is not appropriate. “Molecule” is not a unit of weight, and its physical meaning is: ① a certain number of molecules of a substance, that is, 6.02 × 10 ~ (23) molecules; ② their total weight, expressed in grams, Its molecular weight. The physical quantity should be expressed as M g / mol (M is the molecular weight). For example, a substance 0.2 grams molecular weight of 3.6 grams, one gram molecular weight: 3.6 grams ÷ 0.2 grams of molecules = 18 grams / mole. Two examples cited by Comrade Zhang Haoruo can be calculated as follows: