问题 填空题

“探险队员”——盐酸,不小心走进了化学迷宫,不知怎样走出来,因为迷宫有许多“吃人的野兽”(即能与盐酸反应的物质或水溶液),盐酸必须避开它们,否则就无法通过。

(1)请你帮助它走出迷宫       (请用图中物质前的序号连接起来表示所走的路线)。

(2)在能“吃掉”盐酸的化学反应中,属于酸碱中和反应的有       个,属于氧化还原反应的有       个,其中能“吃掉”盐酸的盐是       ,写出该反应的离子方程式:                             

(3)在不能与盐酸反应的物质中,属于电解质的是       ,属于非电解质的是       (填写物质序号)。

(4)如果将盐酸换成氯气,它能沿着盐酸走出的路线“走出”这个迷宫吗?为什么?                                                               

答案

(1)③⑥⑩⑦⑪⑫(2)2;1;Na2CO3;CO32-+2H=CO2↑+H2O (3)⑥⑪;③⑩(4)不能,因为氯气有强氧化性,遇到二氧化硫、铜时都会发生氧化还原反应而被“吃掉”。

(1)图中物质③、⑥、⑩、⑦、⑪、⑫均不与盐酸反应,沿该路线可走出迷宫。(2)盐酸与NaOH、Ca(OH)2的反应属于酸碱中和反应,与Zn的反应属于氧化还原反应,能“吃掉”盐酸的盐是Na2CO3,该反应的离子方程式为CO32-+2H=CO2↑+H2O。(3)在不能与盐酸反应的物质中,属于电解质的是H2SO4、NaCl,属于非电解质的是CO2、SO2。(4)如果将盐酸换成氯气,它沿着盐酸走出的路线不能“走出”这个迷宫,因为氯气有强氧化性,遇到二氧化硫、铜时都会发生氧化还原反应而被“吃掉”。

选择题
阅读理解

阅读理解

    Do you want to improve the way you study? Do you feel nervous before a test? Many students say

that a lack of concentration is their biggest problem. It seriously affects their ability to study, so do their

test results.

    If so, use these tips to help you.

Study Techniques

    You should always study in the same place. You shouldn't sit in a position that you use for

another purpose. For example, when you sit on a sofa to study, your brain will think it is time to relax.

Don't watch TV while you are studying. Experts warn that your concentration may be reduced by 50

percent if you attempt to study in this way. Always try to have a white wall in front of you, so there is

nothing to distract (make less concentrated) you. Before sitting down to study, gather together all the

equipment you need. Apart from your textbooks, pens, pencils and knives, make sure you have a

dictionary. If your study desk or table is needed when you are not studying, store all your equipment in

a box beside it   .

     Your eyes will become tired if you try to read a text which is on a flat surface. Position your book

at an angle of 30 degrees.

     Be realistic and don't try to complete too much in one study period. Finish one thing before

beginning another. If you need a break, get up and walk around for a few minutes, but try not to

telephone a friend or have something to eat.

Test-taking Skills

     All your hard work will be for nothing if you are too nervous to take your test. Getting plenty of rest

is very important. This means do not study all night before your test! It is a better idea to have a

long-term study plan. Try to make a timetable for your study which lasts for a few months.

     Exercise is a great way to reduce pressure. Doing some form of exercise every day will also improve

your concentration. Eat healthy food too.

     When you arrive in the examination room, find your seat and sit down. Breathe slowly and

deeply. Check the time on the clock during the test, but not too often. Above all, take no notice of

everyone else and give the test paper your undivided attention.

1. Which of the following statements is true according to the passage?

A. You should study in a different place every day, so you don't get bored.

B. Your concentration will improve if you study and watch TV at the same time.

C. Check the time during the exam at a certain time.

D. Staying up all night and studying is tiring, but you will learn a lot using this method.

2. What does the underlined word "it" refers to?

A. Your study desk or table.  

B. Your textbook.

C. Your dictionary.          

D. The equipment you need.

3.  What can be inferred from the passage?

A. You shouldn't look at everyone else during the test.

B. You will have enough energy to deal with your study and exams by eating healthy diet.

C. You'll concentrate more if there is nothing to distract you.

D. If you feel tired during study, you can walk around for a few minutes.