题目
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碳和铜的混合物在空气中加强热,碳和铜均完全氧化后,冷却称重,发现固体总质量未变,试计算原混合物中碳的质量分数。
答案:解:设原混合物中含Cu的质量为x,C的质量为y。根据题意知:Cu的质量加C的质量等于CuO的质量,所以生成CuO的质量为(x+y)。 解得: 故