将7.81gNaCl和KI的混合物溶解于水,通入足量的氯气充分反应,然后把溶液蒸干灼烧,

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  • 设原混合物中含NaClxmol,含KIymol,则:

    58.5x + 166y = 7.81……………………………………………………………(1)

    58.5x + 74.5y = 4.15……………………………………………………………(2)

    解(1)和(2)得:

    x =0.02 y = 0.04

    (1)m(NaCl) = 58.8g/mol * 0.02mol = 1.17g

    w(NaCl) = 1.17g/7.81g*100% = 15.0%

    (2) n(AgCl) = n(NaCl) = 0.02mol

    m(AgCl) = 143.5g/mol * 0.02mol = 2.87g

    n(AgI) = n(KI) = 0.04mol

    m(AgI) = 235g/mol * 0.04mol = 9.4g

    沉淀总质量 = 87g + 9.4g = 12.27g

    答:……………………………………………………