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问题 选择题

取a g某物质在氧气中完全燃烧，将其产物跟足量的过氧化钠固体完全反应，反应后固体的质量增加小于a g。下列物质中能满足上述结果的是

A．H2　和　CO

B．葡萄糖

C．蔗糖

D．甲酸

答案

答案：D

上述四个选项的物质完全燃烧后产物都是水和二氧化碳，

2Na2O2＋2H2O==4NaOH＋O2↑      每个Na2O2 相当于增加了1个H2

2Na2O2＋2CO2==2Na2CO3＋O2↑   每个Na2O2相当于增加了1个CO

所以只要满足CO、H2、Cm(H2O)n这种最简式的化合物反应后固体的质量均不变，只有D不符合Cm(H2O)n

点评：本题利用质量守恒定义，找到最终增加质量的来源，这是解题的关键。

问答题

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上述来往函电中，哪几则属于发盘？（5分）
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多项选择题

溶剂的选择是为了优化涂料的施工性和湿膜性，具体影响到（）

A、流挂

B、流平

C、气泡

D、漆膜外观
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