问题 推断题

X、Y、Z三种物质有如下图所示的转化关系:

回答以下问题:

(1)写出下列物质的化学式X            ,甲__________,乙___________;

(2)写出下列反应的化学方程式:

①乙与Z                                       

②X与NaOH                                   

答案

(1)MgSO4,BaCl2,AgNO3

(2)MgCl2+2AgNO3=Mg(NO3)2+2AgCl↓;MgSO4+2NaOH=Mg(OH)2↓+Na2SO4

X能与硝酸钡反应生成硝酸镁,故X中含有镁离子,要与硝酸钡反应,X中还需要含有硫酸根,故X是硫酸镁;硫酸镁能与氢氧化钠溶液反应生成Y,故Y可能是氢氧化镁,氢氧化镁与盐酸反应生成氯化镁,故Z可能是氯化镁,氯化镁能与乙反应生成硝酸镁,故乙可能是硝酸银;硫酸镁能与甲反应生成氯化镁,故甲可能是氯化钡,带入框图,推断合理;

(1)X是硫酸镁,甲是氯化钡,乙是硝酸银,故填:MgSO4,BaCl2,AgNO3;(2)①氯化镁能与硝酸银反应生成硝酸镁和氯化银沉淀:

MgCl2+2AgNO3=Mg(NO3)2+2AgCl↓;

②硫酸镁能与氢氧化钠溶液反应生成氢氧化镁沉淀和硫酸钠:

MgSO4+2NaOH=Mg(OH)2↓+Na2SO4

阅读理解

June 5 is World Environment Day.This makes us pay more attention to our environment and the need to protect it.

When Wang Baoxuan,a Beijing high school boy,finishes his exercise books,he does not throw them away.He puts them in the big box in the corner of his classroom.Other students do so.Then the exercise books are sold to a paper-factory in Beijing.The paper is collected and used again by students and teachers in the school.At the same time,the money made from selling the paper goes towards schools in Inner Mongolia  for planting trees and grass.During spring time,the sandstorms often attack here.

Wang’s school is one of the schools in the capital that take part in the “green promise”environmental protection activity.So far,nearly 210,000 students have taken part in the activity,collecting more than 174 kilograms of waste paper.

“There are some environment problems in the city,such as sandstorms.We should do our duty and encourage others to do so as well.”Said Wang.

Vice-premier Zeng Peiyan has written a letter to the teachers and students to encourage them to go on taking part in the environmental protection.

小题1:What do Wang Baoxuan and his schoolmates do with the waste exercise books?

A.Throw them away

B.Collect and sell them

C.Cut them into pieces

D.Give them to the students in Inner Mongolia小题2:What is the money from selling the paper used for?

A.Buying new exercise books

B.Helping poor students

C.Planting trees and grass

D.Being their pocket money小题3:What can we infer(推断)from the third paragraph?

A.Many years later,students will have no exercise books to use.

B.Many years later,there will be no waste paper.

C.Many years later,the sandstorms will be weaker in Beijing.

D.Many years later,Beijing will be much dirtier.

判断题