题干

右图为实验室制取少量乙酸乙酯的装置图。下列关于该实验的叙述中不正确的是(   )

A:向a试管中先加入浓硫酸,然后边摇动试管边慢慢加入乙醇,再加乙酸

B:试管b中导气管下端管口不能浸入液面的目的是防止实验过程中产生倒吸现象

C:制得的乙酸乙酯是一种无色透明、有香味的油状液体

D:向a试管中加入几块碎瓷片的作用是防止加热时液体暴沸

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答案(点此获取答案解析)

A

同类题5

阅读下面短文,从短文后各题所给四个选项(A、B、C和D)中,选出可以填入空白处的最佳选项,并在答题卡上将该项涂黑

    Many years ago, Dad worked as a farmhand(农场工人).At that time, he had a horse. Every Saturday he 1to the town after dinner and spent a few hours on social 2 with other farmhands, such as drinking, chatting, and playing cards in the cafe. On Saturday evenings, the cafe was 3 because many farmhands were there. Before midnight Dad returned home on his horse, quite satisfied with his 4.In his words, he 5 thought of changing his job.

    At the age of 31,Dad married my mother who was a schoolteacher. In the following spring I came 6 into the world. Life became hard, so my mother felt 7.She told Dad that they must make a 8.

    My mother had 9 of how some famous persons, especially Thomas Edison who was born in a poor family, fought against fate and achieved greatness and 10.And she 11 that I would some day become a great leader 12 men or cities and Dad should be a successful businessman. So she 13 Dad to give up his job as a farmhand, sell his horse and 14 a small business of his own. And I went to high school and college. She even sent me abroad for 15 education when I graduated from college. Under the drive of my mother's hope, Dad and I 16 what we have today. Dad runs a big international 17 and I am a successful lawyer 18 great fame in my country,19 not a leader as my mother expected.

    Dad said, without my mother, we wouldn't be what we are today; at least, he would remain a farmhand.20 he got a lesson of life --- sometimes we really need drive from outside.