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【简答题】
有Na 2 CO 3 、NaHCO 3 、CaO和NaOH组成的混合物28.2g，把它们溶于足量的水，充分反应后，溶液中Ca 2+ 、CO 3 2— 、HCO 3 — 均转化为沉淀，将容器中的水分蒸干，最后得到白色固体物质共30g。则下列有关叙述错误的是 A．原混合物中含Na 2 CO 3 0.1 mol B．原混合物中n(Na 2 CO 3 )+n(NaHCO 3 )=n(CaO) C．30g固体中一定存在n(CaCO 3 )＜n(NaOH) D．不能确定原混合物中NaOH的质量
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