题干

为探究一溴环己烷()与NaOH的醇溶液共热发生的是水解反应还是消去反应,甲、乙、丙三位同学分别设计如下三个实验方案:
甲:向反应混合液中滴入稀硝酸中和NaOH,然后再滴入AgNO3溶液,若有浅黄色沉淀生成则可证明发生了消去反应。
乙:向反应混合液中滴入溴水,若溶液颜色很快褪去,则可证明发生了消去反应。
丙:向反应混合液中滴入酸性KMnO4溶液,若溶液颜色变浅,则可证明发生了消去反应。
其中正确的是

A:甲

B:乙

C:丙

D:上述实验方案都不正确

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答案(点此获取答案解析)

D

同类题4

根据短文内容,从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。

    Taking good notes is a time-saving skill that will help you to become a better student in several ways. ____ Second, your notes are excellent materials to refer to when you are studying for a test. Third, note-taking offers variety to your study time and helps you to hold your interest.

    You will want to take notes during classroom discussions and while reading a textbook or doing research for a report. ____ Whenever or however you take notes, keep in mind that note-taking is a selective process. ____

The following methods may work best for you.

●Read the text quickly to find the main facts and ideas in it.

●Carefully read the text and watch for words that can show main points and supporting facts.

●Write your notes in your own words.

____

●Note any questions or ideas you may have about what was said or written.

    As you take notes, you may want to use your own shorthand(速记). When you do, be sure that you understand your symbols and that you use them all the time. ____

A. Use words, not complete sentences.

B. There are three practical note-taking methods.

C. You must write your notes on separate paper.

D. Otherwise, you may not be able to read your notes later.

E. You will also want to develop your own method for taking notes.

F. That means you must first decide what is important enough to include in your notes.

G. First, the simple act of writing something down makes it easier for you to understand and remember it.