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问题 选择题

下列解释实验事实的离子方程式正确的是                          （   ）

A．漂白粉中滴加稀盐酸增强漂白性： Ca(ClO)2+2H+＝Ca2++2HClO

B．向明矾溶液中滴入石蕊试液，溶液变红：Al3++3H2O=Al(OH)3↓+3H+

C．Na2O2与H2O反应制备O2：Na2O2+H2O＝2Na++2OH-+O2↑

D．双氧水滴加到酸性高锰酸钾溶液中，紫色褪去、产生大量气泡：2MnO4-+5H2O2+6H+＝2Mn2++5O2↑+8H2O

答案

答案：D

题目分析：A不正确，次氯酸钙应该用离子符号表示；铝离子水解是可逆反应，生成的是氢氧化铝胶体，B不正确；C中没有配平，应该是2Na2O2+2H2O＝4Na++4OH-+O2↑，所以正确的答案选D。

点评：该题是高考中的高频题，属于中等难度的试题，侧重对学生能力的培养和训练。该题需要明确判断离子方程式正确与否的方法一般，即（1）检查反应能否发生。（2）检查反应物、生成物是否正确。（3）检查各物质拆分是否正确。（4）检查是否符合守恒关系（如：质量守恒和电荷守恒等）。（5）检查是否符合原化学方程式，然后灵活运用即可。该题有助于培养学生分析问题、解决问题的能力。

单项选择题 A1/A2型题

不属于通假字的是（）

A."乃勤求古训，博采众方，撰用《素问》、《九卷》"中的"撰"

B."并平脉辨证，为《伤寒杂病论》，合十六卷"中的"平"

C."经络府俞，阴阳会通"中的"俞"

D."蒙蒙昧昧，悫若游魂"中的"意"

E."至齐之得，犹慈石取铁"中的"慈"
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单项选择题

When I was young, my parents ran a snack bar in our small town.One evening in early April, my mother told me to fill in at the snack bar (1) a worker who had the flu. I told her I would mess it up, (2) I had never worked at the bar before. I (3) that instead of making money, I would end up owing it."You can do it," said my mother," (4) , you won’t get much business until lunch. ""But I’ll never remember the orders, and I’m no good (5) money. Please, Mom, don’t (6) me."Then I’ll help you", she said.I shrugged my shoulders. I thought my mother’s (7) was a bad one, but I (8) .When I got to the bar the next day, I found my mother was (9) . Because the weather that day was rainy and cold, people wanted hot snacks and drinks. (10) , I was really slow at taking the orders and making change. The line of people grew, and everybody seemed (11) , I was so nervous that my hands shook, and I (12) a cup into pieces. What a mess! Then my mother came to (13) me, and she also showed me how to make (14) . If someone gave me $ 5 for something that cost $ 3.25, I handed over (15) quarters and a dollar and said, "75 cents makes four dollars, plus one dollar makes five. " Things went more (16) after that.By the end of the day, I could remember orders, (17) the bill, and make change quickly with a smile. I was even a little (18) when the sun came out and dried up business. My mother said she was proud of me, and when she (19) that I work at the snack bar again next year, I did not even shrug. I was too busy (20) the restaurant I would open one day.

 

第（9）空应选择（）

A．angry

B．sad

C．wrong

D．ashamed
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