问题 填空题

(8分)实验装置的设计和组装是一个改进变化的过程,请观察下列装置回答相关问题。

(1)如果实验室用KClO3与MnO2混合加热制O2,可选用上述      (填编号)作为发生装置。反应的化学方程式为                                 

(2)根据B装置的适用条件改进后得到C装置。B装置中发生反应的化学方程式是         ,此时发生装置选用B(或C)而不选用A的理由是      。下列实验室气体的制取可选用上图中C、E作为制气装置的是(填编号)    

①用过氧化氢溶液与二氧化锰混合制氧气    

②用锌粒与稀硫酸反应制取氢气

③用无水醋酸钠固体与碱石灰固体在加热的情况下制CH4

(3)F 装置从a、b中某一个接口进气,可以代替D、E 装置收集气体,并且可以减少气体向空气中的逸出。为了检验F装置的气密性,某同学对F装置进行了如图所示的处理。检查气密性的方法是:先将b端导管口放入水中,然后           ,再用                 ,观察b端水中管口是否有气泡冒出。现用A、F装置来制取并收集氧气,连接A装置的应是    口(选填“a”或“b”)。

答案

(1) A(1分);2KClO32KCl  +  3O2 ↑(1分);(2)CaCO3 + 2HCl  =  CaCl2 + CO2 ↑+2H2O(1分);反应物是固体和液体,而且不需要加热(1分);②(1分)

(3)夹住a处的橡皮管(1分);用双手捂住集气瓶或用热毛巾捂住集气瓶(1分);a (1分).

题目分析:(1)用KClO3与MnO2混合加热制O2,符合给固体加热制取气体,可选用A作为发生装置,反应条件为二氧化锰和加热,反应物为氯酸钾,生成物为氯化钾和氧气;(2)大理石的主要成分是碳酸钙,与氯化氢反应生成氯化钙、二氧化碳和水;用B装置,因为反应固液混合制取气体不需要加热,①用过氧化氢溶液与二氧化锰混合制氧气及②用锌粒与稀硫酸反应制取氢气均符合;(3)检验F装置的气密性:先将b端导管口放入水中,然后夹住a处的橡皮管,再用用双手捂住集气瓶或用热毛巾捂住集气瓶,观察b端水中管口是否有气泡冒出。因为氧气密度比空气大,故应用向上排空气法收集,故应将氧气从a口进入。

判断题
阅读理解

In the kitchen of my mother's houses there has always been a wooden stand with a small notepad and a hole for a pencil.

I'm looking for paper on which to note down the name of a book I am recommending to my mother. Over forty years since my earliest memories of the kitchen pad and pencil, five houses later, the current paper and pencil look the same as they always did. Surely it can't be the same pencil. The pad is more modern, but the wooden stand is definitely the original one.

"I'm just amazed you still have the same stand for holding the pad and pencil after all these years." I say to her, walking back into the living-room with a sheet of paper and the pencil. "You still use a pencil. Can't you afford a pen?"

My mother replies a little sharply. "It works perfectly well; I've always kept the stand in the kitchen. I never knew when I might want to note down an idea, and I was always in the kitchen in these days. "

Immediately I can picture her, hair wild, blue housecoat covered in flour, a wooden spoon in one hand, the pencil in the other, her mouth moving silently. My mother smiles and says, "One day I was cooking and watching baby Pauline, and I had a brilliant thought, but the stand was empty. One of the children must have taken the paper. So I just picked up the breadboard and wrote it all down on the back. It turned out to be a real breakthrough for solving the mathematical problem I was working on."

This story, which happened before I was born, reminds me how extraordinary my mother was, and is also a gifted mathematician. I feel embarrassed that I complain about not having enough child-free time to work. Later, when my mother is in the bathroom, I go into her kitchen and turn over the breadboards. Sure enough, on the back of the smallest one, are some penciled marks I recognize as mathematics. Those symbols have traveled unaffected through fifty years, rooted in the soil of a cheap wooden breadboard, invisible exhibits at every meal.

小题1:Why has the author's mother always kept the notepad and pencil in the kitchen?

A.To leave messages.

B.To list her everyday tasks.

C.To note down math problems.

D.To write down a flash of inspiration.小题2:What is the author's original opinion about the wooden stand?

A.It has great value for the family.

B.It needs to be replaced.

C.It brings her back to her lonely childhood.

D.It should be passed on to the next generation.小题3:The author feels embarrassed for____________.

A.blaming her mother wrongly

B.giving her mother a lot of trouble

C.not making good use of time as her mother did

D.not making any breakthrough in her field小题4:What can be inferred from the last paragraph?

A.The mother is successful in her career.

B.The family members like traveling.

C.The author had little time to play when young.

D.The marks on the breadboard have disappeared.