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混合物中某元素质量分数的计算,已成为初中化学的考查热点。纵观这类题目,不难发现组成混合物的各物质,在元素组成上多少有些相同之处,其中有些是需要将化学式变形后才能寻找出相同部分的,可以依据同一部分中元素间的质量定比关系,列式解题。下面举例说明其解法。1 无机物型 例1 已知(NH_4)_2SO_4和(NH_4)_2HPO_4的混合物中,含氮质量分数为21.2％。则含氧元素的质量分数为( )。
The calculation of the mass fraction of an element in a mixture has become a hot spot for junior chemistry chemistry. Looking at such problems, it is not difficult to find that the substances that make up the mixture are somewhat identical in their elemental composition. Some of them need to be chemically deformed to find out the same part, and can be based on the quality of the elements in the same part. Than the relationship, columnar problem solving. The following example illustrates its solution. 1 Inorganic Type Example 1 It is known that the mixture of (NH_4)_2SO_4 and (NH_4)_2HPO_4 has a nitrogen content of 21.2%. The oxygen content of the mass fraction ().