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在化学中有一些问题用常规法去解决很烦,但是用到转化的思想去解决就很简单了。一、利用相对分子量和相对原子量的转化例一:现有NaHCO3和MgCO3的混合物,求出C元素的质量分数?解析:Na的相对原子量为23,H的相对原子量为1,Mg的相对原子量为24。NaHCO3和MgCO3的相对分子量都为84。NaHCO3中C元素的质量分数=12/84=1/7=14.3%。MgCO3中C元素的质量分数=12/84=1/7=14.3%。所以C元素的质量分数为14.3%。
There are some problems in the chemical routine to solve the annoying, but the idea of using transformation to solve it is very simple. First, the use of relative molecular weight and relative atomic weight conversion Example 1: The existing mixture of NaHCO3 and MgCO3, to find the mass fraction of C element? Analysis: Na relative atomic weight of 23, H relative atomic weight of 1, relative atomic weight of Mg twenty four. The relative molecular weights of NaHCO3 and MgCO3 are both 84. The mass fraction of C element in NaHCO3 = 12/84 = 1/7 = 14.3%. The mass fraction of C element in MgCO3 = 12/84 = 1/7 = 14.3%. So the mass fraction of C element is 14.3%.