题干

下列有关实验的图示及分析均正确的是(    )

选项

实验目的

实验图示

实验分析

A

实验室用酸性高锰酸钾溶液滴定草酸溶液

摇瓶时,使溶液向一个方向做圆周运动,勿使瓶口接触滴定管,溶液也不得溅出。

B

石油分馏时接收馏出物

为收集到不同沸点范围的馏出物,需要不断更换锥形瓶。

C

测定锌与稀硫酸反应生成氢气的速率

实验中,需测定的物理量是反应时间和生成氢气的体积。

D

用四氯化碳萃取碘水中的碘

充分振荡后静置,待溶液分层后,先把上层液体从上口倒出,再让下层液体从下口流出。

A:A   

B:B   

C:C   

D:D

上一题 下一题 0.0难度 选择题 更新时间:2019-12-12 09:51:01

答案(点此获取答案解析)

A

同类题5

阅读理解

    What did you do on April 23, World Book Day, last year? Did you find some interesting books to read? Now let me introduce some good books for you to read.

Title: Dear Andreas
Author: Long Yingtai&Andreas

Andreas is a college student studying in Germany. His mother is a writer working in Taiwan. By writing letters to each other for more than three years, Long Yingtai says she clearly understands what an 18-year-old man is like, Andreas says he knows his mother better. This is a great book full of love. Don't miss it.
Title: Climate Change+2 Degrees
Author: Yamamoto Ryoichi

If the earth's temperature went up 2℃, what would happen? In this book we learn about the history, today's situation and the future of global warming. The author also tells us proper and useful ways to protect our world.
Title: The Methods and Madness Inside Room 56
Author: Rafe Esquith

Perhaps the most famous fifth-grade teacher in America, Rafe Esquith, helps his children understand literature, love life, and become happy, self-confident people using his successful methods in his Los Angeles public school classroom. He has created surprising miracles. This is a powerful book. You'd better read it.
Title: The Last Lecture
Author: Randy Pausch

Randy Pausch, a professor from New York was asked to give a lecture. He knew it would probably be his last lecture, because he was dying of illness. His lecture wasn't about dying, but about getting over the difficulties, helping others to realize their dreams.