题目

控制适合的条件，将反应设计成如右图所示的原电池。下列判断不正确的是    A. 反应开始时，乙中石墨电极上发生氧化反应    B. 反应开始时，甲中石墨电极上Fe3+被还原    C. 电流计读数为零时，反应达到化学平衡状态    D. 电流计读数为零后，在甲中溶入FeCl2固定，乙中石墨电极为负极 答案：答案D 【解析】乙中I－失去电子放电，故为氧化反应，A项正确；由总反应方程式知，Fe3＋被还原成Fe2＋，B项正确；当电流计为零时，即说明没有电子发生转移，可证明反应达平衡，C项正确。加入Fe2＋，导致平衡逆向移动，则Fe2＋失去电子生成Fe3＋，而作为负极，D项错。There are two main sets of Olympics---the Winter and the Summer Olympic, and both 【1】 （hold）every four years on 【2】 regular basis .In the ancient Olympics, slaves 【3】women were not allowed 【4】（join）in the Games .But nowadays【5】（athlete）from any country can take part if they have reached the 【6】（agree）standard . For each Olympics ,a special village will be built for all the athletes to live 【7】 ,a main reception 【8】 （build）,several stadium for competition ,and a gymnasium as well. Every country wants the opportunity to host the Olympic Games .【9】 is not only a great responsibility but also a great honour to be chosen .And the motto of the Olympics is “Swifter ,Higher and 【10】（strong）”.