FeCl3、CuCl2的混合溶液中加入铁粉，充分反应后仍有固体存在，则下列判断不正确的是
A 加入KSCN溶液变红色 B 溶液中一定含Fe2+
C 溶液中一定含Cu2+ D剩余固体中一定含Cu
AC
分阶段分析
①、当固体为铁、铜时，溶液中的Fe3+、Cu2+全部参加反应生成Fe2+和Cu，反应的反应方程式为：2FeCl3+Fe=3FeCl2
CuCl2+Fe=Cu+FeCl2
所以溶液中一定没有Fe3+、Cu2+，一定含有Fe2+；
②当固体为铜时，溶液中一定没有Fe3+，Cu2+恰好全部参加反应或部分反应生成Fe2+和Cu，
所以溶液中一定没有Fe3+，可能含有Cu2+，一定含有Fe2+；
A、溶液中一定不含Fe3+，所以加入KSCN溶液不变红色，故A错误．
B、通过以上分析知，溶液中一定含有Fe2+，故B正确．
C、通过以上分析知，溶液中可能含有Cu2+，故C错误．
D、通过以上分析知，剩余固体中一定含Cu，故D正确．
故选A、C．
根据短文内容,从下框的A～F选项中选出能概括每一段主题的最佳选项,选项中有一项为多余项。
We all have weaknesses and strengths-no matter who we are. Sometimes the weaknesses seem to outweigh the strengths and sometimes it's the other way around. Some people get sick easily. Some struggle to manage their finances properly. Some people are hopeless communicators and struggle with relationships. 2. ________ Many people leave it and accept it as just bad luck-but not everyone. Some people facing huge limitations still manage to achieve tremendous things. They rise above their weaknesses and do not allow them to limit their possibilities. 3. ________ I attended a school prizegiving ceremony not so long ago and the guest speaker was Andrew Becroft, who had a severe stutter(结巴) as a child. Instead of allowing this to limit him, he chose to work hard to overcome it. He is now the Principal Youth Court Judge for New Zealand. Not only did he become successful, but he did so in a profession where he had to speak in front of others regularly -where his weakness is front and center for all to see. If he hadn't worked on his speaking ability, it would have been very limiting to his life and career prospects. 4. ________ You can find similar people on New Zealand News channels, and I suspect the same in other countries. There are a number of presenters and reporters who have a noticeably unusual manner of speaking. Perhaps they have a lisp(咬舌), or they have a strange accent or pitch of voice. These people have succeeded in spite of what would be appear to be a weakness in their profession. 5. ________ Lots of people face far more significant limitations than you do. They may be missing limbs or are born into extreme poverty. But no matter what the limitation, you will always find people who have overcome it. |