下列反应的离子方程式及对应的说法都正确的是( ) A．碳酸氢

问题选择题

下列反应的离子方程式及对应的说法都正确的是( )

A．碳酸氢钙溶液加到醋酸溶液中：Ca(HCO₃)₂+2CH₃COOH=Ca²^＋+2CH₃COO^－+2CO₂↑+2H₂O

B．用惰性电极电解氯化镁溶液： 2Cl^—+ 2H₂O2OH^—+ H₂↑+ Cl₂↑

C．电解精炼铜的阳极反应式只有：Cu - 2e-= Cu²⁺

D．在氯化亚铁溶液中加入稀硝酸：3Fe²⁺+4H⁺+ NO₃^-=3Fe³⁺+NO↑+2H₂O

答案

答案：D

题目分析：离子方程式正误判断——注意“七查”。1.“一查”是否符合客观事实，2.“二查”“反应条件”“连接符号”“↑”“↓”是否使用恰当，3.“三查”拆分是否正确，4.“四查”是否“漏写”离子反应，5.“五查”是否符合三个守恒（1）质量守恒（2）电荷守恒（3）得失电子守恒，6.“六查”是否符合离子配比，7.“七查”反应物的“量”——过量、少量、足量等。A、碳酸氢钙是可溶性强电解质，要拆成离子形式，错误；B、漏掉镁离子和氢氧根生成氢氧化镁的反应，错误；C、粗铜中比铜活泼的金属锌铁等也在阳极放电，错误；D、在氯化亚铁溶液中加入稀硝酸：3Fe²⁺+4H⁺+ NO₃^-=3Fe³⁺+NO↑+2H₂O，正确。

完形填空。
I’m Mike and I come from England. Now I’m 1 at Beijing International School. I’m good 2 all my subjects and I enjoy 3 in China. In 4 , the Olympic Games will be held (举行) in London. It’s 5 news for English people. At that time many foreigners are going to 6 London. My friends and 7 are going to 8 them around Big Ben, Buckingham Palace and 9 because they are very famous in the world. I’m going to 10 with the Chinese 11 in Chinese. But now I don’t know 12 _ Chinese, so I must study it very 13 . From now on, 14 will take me two hours to learn Chinese every day. I’m looking forward 15 the Olympic Games.
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