问题 问答题

化学是一门以实验为基础的自然科学,掌握实验方法以及完成化学实验所必顺的技能是学好化学的关键.试回答下列实验问题:

(1)某同学认为MnO2与浓HCl反应制得的Cl2中含有HCl气体,该同学设计如图1所示装量时行验证.

已知B中试剂为CCl4,则:

①判定含有HCl气体的实验现象为:______.

②装置A中两仪器名称分别为:______、______.

③有人认为可将D装置溶液换成另一溶液,你认为可能为:______.

(2)某课外研究小组设计如图所示的实验过程,用石油化学工业的废气催化剂(主要成份为Ag/α-Al2O3)来回收金属银和α-Al2O3,部分操作过程省略.α-Al2O3作为催化剂的载体,且不溶于硝酸:

Ag/α-Al2O3  

①Ag/α-Al2O3加HNO3溶解可选用图2所示装置中的______ (选填a、b、c)

②实验操作II中,所需要的主要玻璃仪器有______.

③实验操作II中能否用自来水代替蒸馏水?______ (填“能”或“否”)原因是______(结合有关离子方程式给以必要的文字说明)

④操作I中所发生的离子反应方程式:______.

答案

(1)①根据相似相溶原理,非极性溶质极易溶于非极性溶剂,氯气和四氯化碳都是非极性分子,所以氯气极易溶于四氯化碳,当湿润的淀粉碘化钾试纸不变色,说明通过C装置的气体中没有氯气,若D装置中有白色沉淀生成,就说明制取的气体中有氯化氢气体.

故答案为:C装置中淀粉碘化钾试纸不变色,D装置中有白色沉淀生成.

②仪器名称分别为:分液漏斗、烧瓶.

故答案为:分液漏斗、烧瓶.

③氯化氢气体极易溶于水得盐酸溶液,该溶液呈酸性,能和碱发生中和反应,所以可改为氢氧化钠溶液.

故答案为:氢氧化钠溶液.

(2)①为了控制溶液的流量,应选用分液漏斗;该反应中有气体生成,防止液体吸入导气管,所以出气管应短些,故选a.

②实验操作II是分离固体和液体,所以应采取过滤方法,过滤操作用到的玻璃仪器有:起引流作用的玻璃棒,起过滤作用的漏斗,盛装滤液的烧杯.

故答案为:玻璃棒、漏斗、烧杯.

③一般用自来水用氯气消毒,氯气和水反应生成盐酸和次氯酸Cl2+H2O=H++Cl-+HClO,盐酸和氧化铝反应生成氯化铝

6H++Al2O3=2Al3++3H2O,导致回收的氧化铝的质量减少,所以不能用自来水代替蒸馏水.

故答案为:否; 一般用自来水用氯气消毒,氯气和水反应生成盐酸和次氯酸Cl2+H2O=H++Cl-+HClO,盐酸和氧化铝反应生成氯化铝6 H++Al2O3=2Al3++3H2O,导致回收的氧化铝的质量减少,所以不能用自来水代替蒸馏水.

 ④银和稀硝酸反应生成硝酸银和一氧化氮、水,离子方程式为Ag+NO3-+2H+=3Ag++NO↑+H2O.

故答案为:Ag+NO3-+2H+=3Ag++NO↑+H2O.

阅读理解

Charlotte’s Web by E.B. White is a children’s book.

As the story opens,eight-year-old farm girl Fern Arable stops her father from killing a baby pig who is weaker than his brothers and sisters.The little pig,Wilbur,becomes one of the main characters in the story.Later he will be treated as a friend by Charlotte,a wise and loving spider living on the same farm.Wilbur slowly realizes that the farmer will kill him for his meat in a few months ,and Charlotte decides to help him out.She tries many things to keep Wilbur alive.She writes words in her web describing how wonderful Wilbur is and this makes the farm famous.

White creates a sort of modern animal fable(寓言),in which animals can speak both with each other and with Fern.Also there are many great characters in this book.

The society of animals has many lessons to teach children and adults:friendship,sacrifice(牺牲),hope,determination,love,duty,fairness,respect,and many more.

Part of this novel’s success is the fact that the author makes a heroine(女主角)out of a spider,a creature that many people probably dislike.Unlike a lovely little pig or other creatures,a spider is a creature greatly different from humans.White’s Charlotte is a truly wonderful character.He tells the story of Charlotte and her friends in a special way.This is a book that no one could ever dislike.It has much to offer to children as well as to older teens and adult readers.

小题1:According to the descripion of the book,Charlotte ______.

A.is a nice and clever spider

B.often teaches her friends good lessons

C.always sacrifices herself for her friends

D.is disliked by many animals around her小题2:According to the writer,which of the following is a factor in the success of the book?

A.That there are many animals in the book.

B.That the author of the book is very famous.

C.That the author knows children very well.

D.That the author makes a heroine out of a spider.小题3:We learn from the passage that Charlitte’s Web ______.

A.is the most interesting book for children

B.is E.B. White’s only book written for children

C.is a good book not only for children but also for adults

D.is mainly about how animals get along with each other

小题4:What is the purpose of the writer in writing this passage?

A.To introduce the book Charlitte’s Web

B.To discuss what kinds of books are good to read

C.To explain why Charlitte’s Web is a good book

D.To tell us the importance of friendship in our life

问答题 简答题