第一篇：2014年大連中考化學(xué)答案?jìng)€(gè)人版

答案如下

選擇題：C,D,A,C,B,D,B,A,B,C,D,A,D,B,D,填空題：過(guò)濾；氫、氧元素；水；乳化；4鋁+3氧氣====2三氧化二鋁；強(qiáng)；氧氣和水；氧化鐵+3硫酸====硫酸鐵+3水；洗凈擦干（洗凈后涂少許食用油）；

CH4+2O2==（點(diǎn)燃）==CO2+2H2O;SO2;把煤進(jìn)行脫硫處理；石油；減少化石燃料的燃燒，減少空氣污染；

t1;丙；甲；是；37.5%；CaO+H2O====Ca(OH)2，化合反應(yīng)；

2HCL+Mg（OH）2====MgCL2+2H2O,復(fù)分解反應(yīng)；

2H2O2==（MnO2）==2H2O+O2↑，分解反應(yīng)；

每個(gè)人的語(yǔ)言組織都不同，在這里簡(jiǎn)答題主要的給分點(diǎn)我說(shuō)一下吧！

53題（1）保持化學(xué)性質(zhì)的最小微粒是分子，碘固體和碘蒸氣都是由碘分子構(gòu)成，所以碘固體和碘蒸氣都能使淀粉變藍(lán)。（2）氣體間的分子間隔比固體間的分子間隔要大很多，又因?yàn)橘|(zhì)量都相等，所以碘蒸氣的體積遠(yuǎn)大于碘固體的體積。

54題（1）因?yàn)橥涥P(guān)電褥子，電褥子積熱，達(dá)到可燃物著火點(diǎn)，又因?yàn)檠鯕夤┙o不足，故而不完全燃燒冒黑煙，當(dāng)打開(kāi)門窗后，加強(qiáng)了空氣流通，氧氣供給充足，故而瞬間燃起火焰。

（2）立馬拔掉電源或總開(kāi)關(guān)，適當(dāng)澆水降溫后，再開(kāi)窗通風(fēng)。如比較嚴(yán)重可呼叫救援或撥打119.55題：（1）CaCO3 + 2H2O====CaCl2 + H2O + CO2 ↑；密度比空氣大；

（2）2KMnO4== △ ==k2MnO4 + MnO2 + O2 ↑；帶火星的木條；支持燃燒；

（3）防止濺落的熱的生成物炸裂瓶底。

56題：（1）金有很好的延展性，用錘子砸，不會(huì)粉碎，“真金”的密度遠(yuǎn)大于“金”的密度；“銀”的密度等于鋅的密度，“銀”和鋅與稀鹽酸反應(yīng)都有大量氣泡產(chǎn)生。

（2）先取m1克鋅粉于燒杯中，滴加稀硫酸并攪拌直到不產(chǎn)生氣泡為止，計(jì)算出消耗的稀硫酸的質(zhì)量m2，得出稀硫酸的質(zhì)量分?jǐn)?shù)98m1/65m2；取m3克“銅”樣品，適當(dāng)打磨后，于燒杯中滴加稀硫酸并攪拌直到不產(chǎn)生氣泡為止，計(jì)算出消耗的稀硫酸的質(zhì)量m4，最后即可得出Cu的質(zhì)量為：m3—(m1m4）/m2。

（個(gè)人覺(jué)得此題，有點(diǎn)復(fù)雜）

57題：（1）排除水對(duì)本實(shí)驗(yàn)的干擾

（2）NaCl、CaCl2;NaCl、CaCl2、HCl;NaCl、Na2CO3

選用Na2CO3溶液，若無(wú)明顯現(xiàn)象，則溶質(zhì)為NaCl ；若只有沉淀生成，則溶質(zhì)為 NaC、CaCl2；若有氣泡和沉淀生成，則溶質(zhì)為 NaC、CaCl2、HCl。

計(jì)算題步驟我就不寫(xiě)了，直接說(shuō)答案吧！第一問(wèn)：4.2克；第二問(wèn)：2.4%，是生鐵！

第二篇：2014年大連中考英語(yǔ)試題及答案(文字版)

2014年大連中考英語(yǔ)試題及答案（文字版）

第I卷 選擇題(共74分)

I.單項(xiàng)填空(本題共16小題，每小題1分，共16分)

從各題所給的四個(gè)選項(xiàng)中，選出可以填入空白處的最佳選項(xiàng)。

1.Jim is good baskball player.He plays in our school team.A.a B.an C.the D./

2.In America,people start celebrating the New Year 31st December.A.in B.at C.on D.for

3.Many Asian elephants live in India but you can find in other coutries as well.A.him B.them C.her D.it

4.Look at the nice!I've decided to wear it to the party.A.doll B.cup C.poster D.dress

5.In a green school,everyone agrees to be about the environment.A.nervous B.careful C.honest D.rude

6.May I your bike,please? I'll give it back to you soon.A.touch B.bring C.borrow D.buy

7.The British Museum is very serious.Visitors keep quiet.A.may B.might C.can D.must

8.-Who plays the violin ,Sally or Kylie?

-Sally.But she gave the chance to Kylie.A.well B.better C.best D.the best

9.Your handwriting will certainly improve you practise it every day.A.though B.before C.if D.until

10.-What's the book on your table,Lingling?

-Alice's Adventures in Wonderland.Betty it to me from England.A.is sending B.will send C.sends D.sent

11.We want to set off so that we can avoid the heavy traffic.A.early B.recently C.happily D.quietly

12.Most Australians love going to the to swim and surf.A.beach B.forest C.grassland D.desert

13.-is the boy with a pair of glasses?

-My brother,John.A.How B.Who C.Where D.What

14.I know a lot about my pen friend although we've met before.A.often B.always C.never D.usually

15.Many students write to Language Doctor to advice about learning English.A.look through B.ask for C.give up D.worry about

16.-Congratulations!You have won the first prize in the photo competition.-

A.Thank you!B.Good idea!C.Of course D.Enjoy yourself!

II.完形填空(一)(本題共10小題，每小題1分，共10分)

閱讀下面短文，理解其大意，然后從各題所給的四個(gè)選項(xiàng)中，選出可以填入空白處的最佳選擇。

Once there were several scientists in a forest.They were trying to _17 the rarest animal in the world.No one had seen it ,so everyone was _18 and wanted to be the first one to photograph and study it.The animal only came out at night, _19 the scientists did some other studies in the day._20 them,there was a famous scientist named Walter.Every day,he would spend an hour sitting at the desk and putting all his equipment(設(shè)備)in the _21 place.He did this carefully.But other scientists laughed at him because they thought Walter was just wasting _22.One night,the animal appeared _23.The scientists heard its call.But the call didn't last long.The animal was frightened by the _24 made by the scientists while they were scrabbling(忙亂地找)for their cameras and notebooks.On the next morning,the scientist _25 their fingings.Some had tried to record its call,others had noted down how it moved,and the luckiest one had even photographed parts of its tail and legs.They all congratulated each other on what they had found.However,when they saw what Walter had,they were very surprised._26 had taken several complete(完整的)photos,the record of the animal's cry and notes about the animal.They ran to congratulate Walter.They now understood the importance of keeping things in order.Because of that,Walter could find everying quickly in the dark.17.A.feed B.study C.catch D.kill

18.A.relaxed B.tired C.excited D.surprised

19.A.but B.or C.and D.so

20.A.Among B.Beside C.Against D.Except

21.A.clean B.right C.safe D.pubilc

22.A.space B.money C.food D.time

23.A.angrily B.immediately C.suddenly D.quickly

24.A.plans B.noises C.records D.mistakes

25.A.compared B.counted C.sorted D.kept

26.A.They B.It C.He D.You III.閱讀理解(一)(本題共19小題，每小題2分，共38分)

A.閱讀下列短文，根據(jù)短文內(nèi)容，從各題所給的四個(gè)選項(xiàng)中，選出最佳選項(xiàng)。

Passage 1

The school day begins at 8:45.Class teachers meet the class and check who is present and absent at the beginning of the day.We meet as a whole school once a week on Fridays.The head teacher speaks to the whole school.Morning lessons begin at 9:05.There are three one-hour lessons with a fifteen-minute break.The lunch break is from 1 pm to 1:45.Afternoon lessons begin at 1:50 and the school day finishes at 4 pm.All students study and take exams in maths,science and English.In addition, they choose one subject from history,geography,Art,Design and Technology,French and Spanish..All students take PHSE(Personal Health and Safety Education)lessons but no exams are offered.After school sports practice and matches are arranged on Wednesday afternoon and Saturday morning.Chess,music,language and theatre clubs also arrange meetings after school.Students may join as many clubs as they like,but should join at least one.The school has a good record in sports.Last year we were champions(冠軍)in football and tennis, and individual students won prizes for swimming and gymnastics.27.The first lesson begins at in the morning.A.7:30 B.8:00 C.8:45 D.9:05

28.The school students once a week on Fridays.A.meet class teachers

B.review their lessons

C.listen to a speech

D.take some exercise

29.All students take an exam in.A.science B.history C.French D.PHSE

30.What can we learn from the passage?

A.School lunch break lasts over one hour.B.School football team wins matches every year.C.Students can join more than one club.D.Students do sports on Wednesday morning.31.What would be the best title for the passage?

A.Abusy school day

B.Our colorful school life

C.My favourite school

D.My happy times at school

Passage2

A subway is not just an important form of transport.It is also a window for other people to learn about local culture.Beijing, China

The Beijing Subway was opened in 1969 and is the oldest subway system in China.It has added some modern technologies.All stations now have touch-screen maps.In some stations, people can also see traditional Chinese culture.For example,on the walls of a few stations of Line 8,there are some pictures of blue and white porcelain(青花瓷).Stockholm, Sweden

The first subway line for Stockholm was opened in 1950.The Stockholm Subway is well-known for its decoration of the stations.It is called the longest art gallery in the world.Over 90 percent of its stations are decorated with paintings.A few stations are decorated with red bedrocks(巖床).This makes you feel as if you are in a cave.London,UK

The London Undergound or the Tube is the oldest subway in the world.It was opened in 1863.During World War II, it was used to protect people form German plane attacks(襲擊)on London.Now, it is a symbol of the city.There is no air conditioning in the trains, so it is very hot in summer.New York,US

The New York City Subway runs 24 hours a day.It has an express train on almost everyline.You can get to your destination(目的地)quickly.The

trains themselves are full of fun;you will see people doing moonwalk dances like Michael Jackson, playing the guitar and singing.32.Whick subway is called the longest art gallery in the world?

A.The BeiJing Subway

B.The Stockholm Subway

C.The London Underground

D.The New York City Subway.33.From the passage , we can know that the London Underground.A.is also called the Tube

B.is the symbol of the UK

C.was well protected during the war

D.is the oldest transport in the world

34.Which of the following is TRUE?

A.Michael Jackson often danced in the New York City Subway.B.Tourists feel cool when they take the London Underground in summer.C.Several stations of the Stockholm Subway are built in caves.D.Some stations of the Beijing Subway are decorated with pictures of porcelain.35.The introduction of the subways mainly shows the of different cities.A.great changes

B.long history

C.local culture

D.public transport

36.The passage may come form.A.a story book

B.a travel magazine

C.a science book

D.a newspaper advertisement

Passage 3

Hold your head up high

I was 15 mohths old, a happy and carefree kid, until the day I fell.It was a bad fall.I landed on a piece of glass that cut my eye badly.from then on, my injured, sightless, cloudy gray eye lived on with me.Sometimes people asked me embarrassing(使人難堪的)questions.Whenever kids played games, I was the “monster”.I was always imagining that everyone looked down on(瞧不起)me.Yet mum would say to me, “Hold your head up high and face the world.” I began to depend on that saying.As a child, I thought mun meant, “Be careful, or you will fall down or bump into something because you are not looking.” As a teenager, I usually looked down to hide my shame.But I found that when I held my head up high, People liked me.In high school I even became the class president, but on the inside I still felt like a monster.All I really wanted was to look like everyone else.When things got really bad, I would cry to my mun and she would look at me with loving eyes and say, “Hold your head up high and face the world.Let them see the beauty that is inside instead of your appearance(外貌).”

My mun's love was the sunshine that made me bright.I had faced hard times, and learned not only to be confident(自信的)but also to have deep compassion(同情)for others.“Hold your head up high” has been heard many times in my home.I say it to my children.The gift my mum gave me will live on.37.The world “carefree”in the first line probably means“ ” in chinese.A.無(wú)憂無(wú)慮的 B.無(wú)拘無(wú)束的 C.小心翼翼的 D.與眾不同的

38.Why did the writer imagine that everyone looked down on her?

A.She felt bad about her appearance.B.She found it hard to act as a monster.C.Kids refused to play games with her.D.People always asked her embarrassing questions.39.Why did the writer's mum say “Hold your head up high”to her?

A.To tell her to be careful.B.To help her hide the shame.C.To stop her from getting hurt.D.To make her more confident.40.From the story, we can know that.A.the writer understood the saying very well as a child

B.the writer felt like everyone else in high school.C.the writer is living with a warm and brave heart now

D.the writer has deep compassion for others all her life

41.The passage is mainly about.A.what the writer experienced when she was 15

B.what the writer did to show thanks for mum's gift

C.how the writer changed herself with mum's love

D.how the writer became confident with her great efforts B.閱讀短文，根據(jù)短文內(nèi)容，從所給的六個(gè)選項(xiàng)中選出可以填入空白處的最佳選項(xiàng)，使短文意思完整、連貫。(有兩項(xiàng)為多余選項(xiàng))

Passage 4

The book that can't wait

One problem a lot of people have with books is that they buy them and then never read them.42 It printed a book in disappearing ink: the text of the book disappears two months after the special package(盒)of the book is opened.It encurages buyers to read it before it goes away.People call this “he book that can't wait”.43 The publisher(出版社)sold out all the first edition at a bookstore in one day, and received“thousands of requests(請(qǐng)求)”for more copies of the book.It also got a lot of media coverage(媒體報(bào)道).As a result,the publisher is planning to publish other works in disappearing ink now.44 But here, we have some suggestions:

First,the book should start disappearing after the reader opens the book for the first time.If the books become very popular in the future, readers will need to read them one at a time.They don't want their books to disappear before they read the frist page.Second, the disappeared book should find a good use._ 45 It would be a more environmentally friendly way to do this.A.The book was a great success.B.It's wrong to throw the books away after reading them.C.In some ways, the idea is pretty clever.D.To work out this problem, a publisher got a brilliant idea.E.Maybe we can use them as notebooks.F.Luckily, some experts invented a book and worked out the problem.IV.情景交際(本題共5小題，每小題2分，共10分)

根據(jù)對(duì)話內(nèi)容，從所給的七個(gè)選項(xiàng)中選出可以填入空白處的最佳選項(xiàng)，使對(duì)話內(nèi)容完整。(有兩項(xiàng)為多余選項(xiàng))

Daming:Hi,Lingling!

Lingling:Hi,Daming!46

Daming:Yes.What's up?

Lingling:Tomorrow is Sally's birthday.47 You know,she's alone in China.Daming:That's a good idea!You are so kind.Lingling:48

Daming:Yes,I'd love to.49

Lingling:At five o'clock in the afternoon.Daming:OK.I'll get to your house on time.Lingling:50

Daming:I will.Bye.Lingling:Bye.A.When will it start?

B.Will you be free tomorrow?

C.Remember to tell Betty!

D.Would you like to come to the party?

E.Where shall we meet?

F.What would you like to drink?

G.I want to hold a party for her in my house.第II卷 非選擇題(共66分)

V.完形填空(二)(本題共13小題，每小題2分，共26分)

A.根據(jù)短文內(nèi)容，用方框內(nèi)所給詞的適當(dāng)形式填空，使短文內(nèi)容完整，(每詞限用一次)

hour before mouth see artist popular draw for

The dog is a real artist

Sam is a 9-year-old dog.He has a hobby:painting.The hobby not only makes him famous,but also makes him rich.Sam has_51 22 paintings.All of them are abstract(抽象派的).When he paints, he holds his brush(畫(huà)筆)in his_52.He likes to start with darker colors_53 moving on to lighter ones.Sam's paintings are _54 in the US.Some sell for as much as $1,700.A woman even bought one as a birthday gift _55 her dog.“He loves painting and would paint for _56 if I left him to it,“said Sam's owner, Mary.Sam was once a rescue(搜救)dog.One day,Mary wanted to teach him something.“I_57dolphins painting and elephants painting,so I thought,why not a dog?”said Mary.She is right.Now Sam is one of the world's greatest animal_58.People call him ”DaVinci in the dog world.”

B閱讀下面短文，在短文的空格內(nèi)填入適當(dāng)?shù)脑~，使其內(nèi)容通順。(每空格限填一詞)Asking the way in different places

I rtavel a lot, and I find out different“styles”of giving directions(方向)every time I ask “How can I get to the post office?”

In Japan, people use landmarks(地面標(biāo)志性建筑物)in their directions_59 most streets don't have names.For example, the Japanese will say to travelers,“Go straight ahead and turn left at the hotel.The post office is across from the bus stop.”

In the countryside of the American Midwest, there are no towns or buildings in many places.Instead of landmarks, people will tell you directions and _60.In Kansas,for example,people will say,“Go north two miles(英里).Turn east,and then go another mile.”

People in Los Angeles,California, have _61 idea of distance.They measure(測(cè)量)distance in time, not miles.“How far away is the opst office?” you ask.“Oh,”they answer,“it's about five minutes from here.”

It's true that a person doesn't know the answer sometimes.What _62 in such a situation? A New Yorkermight say,“Sorry I don't know.” But in Yucatan,Mexico,no one answers“I don't know” People in Yucatan believe that “I don't know” is impolite.They usually give an answer, often a _63 one.A tourist can get very,very lost in Yucatan!

Ⅵ.閱讀理解(二)(本題共5小題，每小題2分，共10分)

閱讀下面短文，根據(jù)短文內(nèi)容，回答下列問(wèn)題。

Ask any group of teenagers in the UK what they most like to eat,and foods like pizzas,pasta,burgers and chips are always mentioned.Many young people would probably also list the local fast-food restaurant as their favorite place.But what teenagers like to eat is not necessarily what they should eat.For a growing body,eating foods with plenty of calcium(鈣),such as milk,yoghurt and cheese,is important because calcium is essential for the development of healthy,strong bones(骨頭).Similarly,foods that are rich in iron(鐵)are good for developing bodies,so it's good for them to eat red meat,bread and green vegetables.Lifestyle habits can be developed during our teenage years,so it is greatly important that young people are educated about what foods are good.In 2005,in order to change eating habits and open teenagers' minds to new tastes,a cook named Jamie Oliver started a “Feed Me Better” project.He worked with teachers and cooks in a number of schools across the UK to provide more healthy school meals.Although some teenagers and parents refused to have a try at first,the project was generally a huge success.The newspapers wrote articles about him and a TV program showed his visits to the schools.No on expects to end the teenage love with fast and junk food,but,hopefully,if projects like “Feed Me Better”continue to give out the right messages,more young people will understand the importance of eating healthily.64.What problem do teenagers in the UK have?

65.Why are milk and bread healthy foods?

66.Why is it important to educate people during their teenage years?

67.Did Jamie Oliver improve school dinners successfully?

68.In order to help teenagers,what does the writer expect people to do?

Ⅶ.寫(xiě)

A.句子翻譯。將下列句子譯成英語(yǔ)。(本題共5小題，每小題2分，共10分)

69.大連有多少人口?

70.杰克不在家，他在圖書(shū)館看書(shū)。

Jack isn't at home.71.我們的教室一天打掃兩次。

72.現(xiàn)在很多人喜歡乘坐高鐵(high-speed train)，因?yàn)樗臁?/p>

73.盡管山很高，但我相信我最終一定能到達(dá)山頂。

,though it is very high.B.書(shū)面表達(dá)(共20分)

74.旅游可以讓人放松身心，增長(zhǎng)見(jiàn)識(shí)??初中畢業(yè)在即，很多同學(xué)想利用暑假去旅游。請(qǐng)你根據(jù)下面的內(nèi)容提示，寫(xiě)一篇短文，通過(guò)你校英語(yǔ)論壇，向大家推薦一個(gè)好去處，并給出旅行建議。

內(nèi)容提示：

1.Where is the best place to go?

2.What is the place special for?

3.What should you pay attention to?

要求：1.中心突出，語(yǔ)意連貫，層次清晰，書(shū)寫(xiě)規(guī)范;

2.文中不得出現(xiàn)真實(shí)姓名、校名;

3.詞數(shù)80左右，開(kāi)頭已給出，不計(jì)入總詞數(shù)。

It's a good idea to go travelling during the summer vacation.I think the best place to visit is____________________________________________________________________

參考答案：

答案： 1— 5 A C B D B 6— 10 C D B C D 11— 15 A A B C B 16 A 17— 21 B C D A B 22— 26 D C B A C D 28 C 29 A 30 C 31 B 32 B 33 A 34 D 35 C 36 B 37 A 38 A 39 D 40 C 41 C 42 D 43 A 44 C 45 E 46 B 47 G 48 D 49 A 50 C

drawn 52 mouth 53 before 54 popular 55 for 56 hours 57 saw 58 artists 59 because 60 distance 61 no 62 happens 63 wrong

答案： 64 They like fast food and they don’t understand the importance of eating healthily.65 They are with plenty of calcium and calcium is essential for the development of healthy, strong bones.66 Lifestyle habits can be developed during our teenage years.67 Yes.68 The writer expects people to eat what they should eat, develop lifestyle habits during teenage years and understand the importance of eating healthily by projects like “Feed Me Better”continue to give out the right messages.69 What’s the population of Dalian? How many people are there in Dalian?

He is reading(books)in the library.71 Our classroom is cleaned / tidied up twice a day.72 Now many people like traveling by high— speed train / taking the high— speed train, because it is faster.73 I believe / am sure that I can reach the top of the mountain at last / in the end / finally.

第三篇：2014年上海中考化學(xué)答案

十力教育春季班 初三化學(xué)

2014年上海中考化學(xué)答案

六、選擇題（共20分）

27、C

32、D

37、D

42、D28、D

33、C

38、A

43、B29、D

34、A

39、B

44、C30、B

35、C 40、B

45、A31、B

36、A

41、A

46、A

七、填空題（共21分）

47、（1）Si

（2）K2CO3（3）N2（4）CO

?Cu?H2O（5）H2?CuO??

（6）CuO（7）1:4（8）6.02×1023

48、（9）A（10）CD（11）硝酸鉀（12）氯化鈉（13）50

（14）降低溫度并加入硒酸鎘（15）降溫結(jié)晶（冷卻熱飽和溶液）

49、（16）升高

（17）2NaOH+CO2→Na2CO3+H2O

（18）進(jìn)行對(duì)照實(shí)驗(yàn)，證明CO2與NaOH發(fā)生反應(yīng)（19）溶液先變紅后褪色，并有氣泡產(chǎn)生

?

八、簡(jiǎn)答題（共19分）

50、（1）試管（2）錐形瓶（3）C

MnO2，?

2KClO?????2KCl?3O2? 3（4）

（5）bac（6）b51、（7）解：設(shè)樣品中鐵的物質(zhì)的量為xmolFe+H2SO4→FeSO4+H2↑

11xmol0.1mol

?

xmol0.1molx=0.1mol答：樣品中鐵的物質(zhì)的量為0.1mol。（8）80%（9）7.052、（10）1、2、1、1（11）無(wú)水硫酸銅

（12）水蒸氣和二氧化碳

（13）固體質(zhì)量不再減少，證明堿式碳酸銅已經(jīng)分解完全。（14）黑色粉末變成紅色

（15）F中液體通過(guò)導(dǎo)管倒流入E中，造成試管炸裂。

（16）不能確定炭粉還原氧化銅的生成物中是否有二氧化碳。

因?yàn)榭赡苡孝僦形捶纸獾膲A式碳酸銅在實(shí)驗(yàn)②中分解，產(chǎn)生二氧化碳?xì)怏w，干擾對(duì)炭粉還原氧化銅反應(yīng)生成物的判斷。

十力教育 化學(xué)教研組 版權(quán)所有第1頁(yè) 靜安校區(qū)：西康路618號(hào)華通大廈18A，Tel：62377379 黃浦校區(qū)：南車站路69弄華教大廈11樓，Tel：54666361

第四篇：2014年畢節(jié)中考化學(xué)答案

2014年畢節(jié)中考化學(xué)答案

一、選擇題

1.D2.A3C4.C5.B6.B7.A8.C

二、填空題

17.小，分解，加熱

18.NO2，不能

19.(1)2H2O ===通電== 2H2 +O2（2）CuO（3）置換反應(yīng)

20.（1）a（2）H2SO4（3）Fe

三、實(shí)驗(yàn)題

21.C和CuO,乙，甲，試管內(nèi)溶液呈藍(lán)色、有黑色固體存在，CuO + H2SO4====CuSO4 + H2O

22.(1)長(zhǎng)頸漏斗，集氣瓶

（2）固體

（3）CH4、NH3

(4)B ,2H2O2==MnO2==2H2O+2

（5）檢查裝置的氣密性，a

四、計(jì)算題

23.（1）314（2）4.8g

24.(1)4.4(2)86.2%

第五篇：大連歷年中考化學(xué)簡(jiǎn)答題(含答案)

大連歷年中考化學(xué)簡(jiǎn)答題（含答案）

1.（2017?大連）（3分）如圖所示，集氣瓶I、II中分別裝有二氧化碳和空氣，把中間的玻璃片抽出，一分鐘后，取下集氣瓶I，將燃著的木條伸入集氣瓶II中，木條熄滅，用微粒的觀點(diǎn)解釋現(xiàn)象。

解：二氧化碳分子和空氣中的氣體分子因不斷運(yùn)動(dòng)而進(jìn)入到彼此分子之間的間隔中（1分），集氣瓶II中的氧分子數(shù)目少，二氧化碳分子數(shù)目多（1分），（不同分子化學(xué)性質(zhì)不同）氧分子能助燃，二氧化碳分子不能助燃（1分），因此木條熄滅。

2.（2017?大連）（4分）運(yùn)用所學(xué)知識(shí)，分析下列事實(shí)中的原理。（1）干草易點(diǎn)燃；濕草不易點(diǎn)燃。

（2）將干草卷成緊實(shí)的粗條狀，外面用一層濕草緊緊包裹。在一端點(diǎn)燃干草后，將火焰吹熄，使干草保持紅熱狀態(tài)，這樣可使火種保持較長(zhǎng)時(shí)間。

解：（1）草的著火點(diǎn)較低，溫度易達(dá)到著火點(diǎn)，所以干草易點(diǎn)燃（1分）。濕草中的水蒸發(fā)吸熱，溫度不易達(dá)到草的著火點(diǎn)，濕草不易點(diǎn)燃。（1分）

（2）緊實(shí)的干草被濕草包裹，與氧氣的接觸面積較?。?分）；“吹熄”火焰后的干草燃燒放熱量少，且濕草吸收部分熱量，溫度較低，因此干草燃燒的速率慢，持續(xù)時(shí)間較長(zhǎng)（1分）

3。（2016?大連）（3分）向充滿二氧化碳的集氣瓶中，加入滴有紫色石蕊溶液的水，約占集氣瓶容積的，立即蓋上玻璃片，用手壓住玻璃片，充分振蕩后將集氣瓶倒置，松開(kāi)手，觀察到，玻璃片沒(méi)有掉落，紫色石蕊溶液變紅。用微粒的觀點(diǎn)解釋以上現(xiàn)象。

解：二氧化碳分子進(jìn)入水分之間，使集氣瓶中的氣體減少壓強(qiáng)變小，部分二氧化碳分子與水分子結(jié)合為碳酸分子，使溶液顯酸性，所以用手壓住玻璃片，充分振蕩后將集氣瓶倒置，松開(kāi)手，觀察到，玻璃片沒(méi)有掉落，紫色石蕊溶液變紅。

4。（2016?大連）（4分）為了便于儲(chǔ)存、運(yùn)輸和使用，通常把氣體加壓儲(chǔ)存在鋼瓶中。（1）儲(chǔ)存和運(yùn)輸氧氣鋼瓶時(shí)，嚴(yán)禁與易燃?xì)怏w鋼瓶混合存放，以防氣體泄漏發(fā)生猛烈爆炸事故。分析混合存放可能發(fā)生爆炸的原因。

（2）使用氧氣鋼瓶時(shí)，若氧氣鋼瓶的瓶嘴上沾有油污，打開(kāi)減壓閥，高壓氧氣噴出后油污會(huì)自燃。解釋油污自燃的原因。

解：（1）氧氣具有助燃性，氧氣泄漏后與可燃性氣體混合物，遇明火很容易發(fā)生爆炸；故填：可燃性氣體與氧氣充分混合，達(dá)到了可燃性氣體的爆炸極限，遇明火就會(huì)發(fā)生爆炸；（2）油污屬于可燃物，溫度達(dá)到了油污的著火點(diǎn)，再與噴出的氧氣接觸，就立刻發(fā)生了燃燒。故填：溫度達(dá)到了油污的著火點(diǎn)，并與氧氣接觸。

5。（2015?大連）（（4分）坩堝鉗夾住一團(tuán)棉花，蘸上酒精后點(diǎn)燃，現(xiàn)察到：開(kāi)始時(shí)酒精蒸氣燃燒。棉花未燃燒；當(dāng)酒精快燃盡時(shí)。棉花開(kāi)始燃燒。分析出現(xiàn)以上現(xiàn)象的原因。解：開(kāi)始時(shí)酒精蒸氣燃燒，棉花未燃燒；因?yàn)樗终舭l(fā)帶走了酒精燃燒產(chǎn)生的熱量，沒(méi)有達(dá)到棉花的著火點(diǎn)，因此開(kāi)始時(shí)，棉花未燃燒；當(dāng)酒精快燃盡時(shí)，溫度達(dá)到了棉花的著火點(diǎn)，棉花開(kāi)始燃燒。

6。（2015?大連）（（3分）將檸檬（一種水果）切片。放入冰箱冷凍后，取出一部分放入真空冷凍環(huán)境中。留在冰箱中的檸搽片，時(shí)間久了會(huì)失去部分水分，真空冷凍環(huán)境中的檸檬片，在短時(shí)問(wèn)內(nèi)會(huì)變成干燥的檸檬片。用微粒的觀點(diǎn)解釋：（1）為什么冷凍后的檸檬片還會(huì)失去水分？

（2）為什么真空冷凍環(huán)境中的檸檬片，在短時(shí)間內(nèi)就會(huì)變干燥？ 解：（1）分子是不斷運(yùn)動(dòng)的，冷凍后的檸檬片中水分子運(yùn)動(dòng)到空氣中；

（2）真空冷凍環(huán)境中，因壓強(qiáng)減小，水分子間的間隔驟然變大，水分子運(yùn)動(dòng)加速并擴(kuò)散，所以短時(shí)間檸檬片會(huì)變干。

7.（2014?大連）（3分）用微粒的觀點(diǎn)解釋下列事實(shí)。（1）碘固體（I2）和碘蒸氣都能使淀粉變藍(lán)。

（2）等質(zhì)量的碘固體和碘蒸氣比較，碘蒸氣的體積遠(yuǎn)大于碘固體。

解：（1）碘固體和碘蒸氣都是由碘分子構(gòu)成的，同種物質(zhì)的分子化學(xué)性質(zhì)相同；（2）等質(zhì)量的碘固體和碘蒸氣，含有的碘分子個(gè)數(shù)相等，碘蒸氣中碘分子之間的間隔遠(yuǎn)遠(yuǎn)大于碘固體分子之間的間隔，所以碘蒸氣的體積遠(yuǎn)大于碘固體。

8。（2014?大連）（4分）某居民早起忘記關(guān)閉電褥子的電源就去上班，下班后發(fā)現(xiàn)臥室門縫冒出黑煙，他立即打開(kāi)門窗，結(jié)果原本只冒黑煙的電褥子瞬間燃起火焰。（1）分析產(chǎn)生上述現(xiàn)象的原因。（2）電褥子著火，應(yīng)采用什么方法滅火？

解：（1）長(zhǎng)時(shí)間充電會(huì)導(dǎo)致電褥子過(guò)熱，溫度達(dá)到可燃物的著火點(diǎn)引發(fā)燃燒，但是臥室內(nèi)氧氣不充足，所以冒黑煙，當(dāng)打開(kāi)門窗時(shí)，空氣流通，空氣中氧氣含量增加，所以迅速燃燒；（2）為了防止觸電，在滅火前應(yīng)先切斷電源，然后再用水澆滅。

9。（2013?大連）（4分）用微粒的觀點(diǎn)解釋下列事實(shí)。（1）空氣是一種混合物。

（2）取一個(gè)透明的玻璃杯，先倒入半杯水，再放入一大塊冰糖，立即在玻璃杯外壁液面位置做上記號(hào)，冰糖完全溶解后液面低于記號(hào)。

故答為：（1）空氣中含有氮?dú)狻⒀鯕?、二氧化碳等多種分子；（2）分子間有間隔，在水分子作用下糖的分子不斷運(yùn)動(dòng)，彼此進(jìn)入對(duì)方的間隔當(dāng)中，使液體體積減小。

10。（2013?大連）（4分）如圖所示，取三根粗細(xì)、長(zhǎng)度均相同的光亮細(xì)鐵絲，將其中兩根分別盤(pán)成螺旋狀，在每根鐵絲一端綁上粗銅絲，另一端系一火柴，點(diǎn)燃火柴，待快燃盡時(shí)，分別插入充滿氧氣的集氣瓶中（預(yù)先放入一些水）。觀察到：Ⅰ、Ⅱ中鐵絲都劇烈燃燒，且Ⅱ中鐵絲燃燒比I中的更劇烈；Ⅲ中鐵絲沒(méi)有燃燒。（1）為什么Ⅲ中鐵絲不能燃燒？

（2）分析Ⅱ中鐵絲燃燒比I中的更劇烈的原因。

解：（1）實(shí)驗(yàn)III中火柴在鐵絲上方，用其火焰內(nèi)焰對(duì)鐵絲加熱，內(nèi)焰溫度低，沒(méi)有對(duì)鐵絲充分預(yù)熱，因此不能達(dá)到鐵絲的著火點(diǎn)；（2）實(shí)驗(yàn)II中鐵絲繞成螺旋狀，增大受熱面積，反應(yīng)更充分。

11.（2012?大連）（3分）用微粒的觀點(diǎn)解釋下列事實(shí)。（1）相同質(zhì)量的液態(tài)水和氣態(tài)水所占體積不同。

（2）水中加入少量蔗糖，靜置一段時(shí)間，最終形成均

一、穩(wěn)定的混合物。

解：（1）氣態(tài)水的水分子之間的間隔大于液態(tài)水水分子之間的間隔，所以它們所占體積不同；

（2）蔗糖分子運(yùn)動(dòng)到水分子之間，最終形成均

一、穩(wěn)定的混合物。

12。（2012?大連）（4分）如圖是面粉爆炸的實(shí)驗(yàn)裝置。（1）點(diǎn)燃蠟燭后，為什么應(yīng)立即并快速鼓入大量空氣？（2）為防止爆炸，面粉加工車間需要保持通風(fēng)，說(shuō)明原理。

解：（1）使面粉飛揚(yáng)充滿裝置，利用燃著的蠟燭引燃面粉，使大量的面粉迅速燃燒，并在短時(shí)間內(nèi)產(chǎn)生大量的熱，使氣體的體積迅速膨脹從而引發(fā)爆炸；

（2）面粉加工車間需要保持通風(fēng)，使產(chǎn)生的面塵能夠及時(shí)的擴(kuò)散出去而能夠有效的防止爆炸的發(fā)生。

13.（2011?大連）現(xiàn)有一瓶無(wú)色、有特殊氣味的液體，是甲醇（CH3OH）或乙醇（C2H5OH）。通過(guò)測(cè)定該液體充分燃燒后生成的二氧化碳和水的質(zhì)量可確定是哪種物質(zhì)，解釋原理。

解：反應(yīng)后生成了二氧化碳和水，則根據(jù)質(zhì)量守恒定律，化學(xué)反應(yīng)前后元素的種類質(zhì)量不變，則反應(yīng)物中一定含有C、H元素；

已知生成的二氧化碳和水的質(zhì)量，則根據(jù)二氧化碳和水的質(zhì)量，利用某元素的質(zhì)量=化合物的質(zhì)量×該元素的質(zhì)量分?jǐn)?shù)可求出碳元素和氫元素的質(zhì)量比；

再根據(jù)碳元素和氫元素的質(zhì)量比即可求得碳元素與氫元素的原子個(gè)數(shù)比；最后與反應(yīng)前甲醇和乙醇中的碳?xì)鋫€(gè)數(shù)比對(duì)照，即可知道是哪種物質(zhì)。

14.（2011?大連）用右圖裝置做硫燃燒的實(shí)驗(yàn)。

（1）硫在空氣中燃燒不如在氧氣中劇烈的原因是 空氣中氧氣濃度比純氧中濃度低。

（2）觀察到實(shí)驗(yàn)現(xiàn)象后，為盡量減少二氧化硫逸散到空氣中，要使燃燒的硫立即熄滅，應(yīng)采取的措施是 伸入氫氧化鈉溶液中；，依據(jù)的滅火原理是 降溫，、隔絕氧氣。

15.（2010?大連）冬季可用煤爐取暖，分析下列做法或現(xiàn)象中的原理。（1）生煤爐時(shí)，需先引燃木材。（2）開(kāi)始時(shí)煤燃燒較弱，過(guò)一會(huì)變得劇烈。（3）煤層上方有時(shí)會(huì)出現(xiàn)藍(lán)色火焰。（4）用扇子扇爐火，越扇越旺。

解：（1）木材燃燒放出熱量，煤吸收熱量后溫度升高，當(dāng)溫度達(dá)到煤的著火點(diǎn)時(shí)，煤就燃燒起來(lái)。

（2）燃燒放熱，使周圍的煤達(dá)到著火點(diǎn)，燃燒旺盛。

（3）燃燒產(chǎn)生的二氧化碳被熱的碳還原生成一氧化碳，一氧化碳燃燒能夠發(fā)出藍(lán)色火焰。（4）增加空氣量，從而使煤與氧氣的接觸面積增大，促進(jìn)煤的燃燒。

16.（2010?大連）如圖所示，將蠟燭和裝有堿石灰（主要成分為氧化鈣和氫氧化鈉的混合物）的玻璃管固定在已調(diào)平的天平左盤(pán)，往右盤(pán)加砝碼至天平平衡。點(diǎn)燃蠟燭，使燃燒產(chǎn)物全部被堿石灰吸收。

（1）蠟燭燃燒過(guò)程中，天平的（填“左”或“右”）盤(pán)逐漸下沉。

（2）根據(jù)質(zhì)量守恒定律解釋天平失去平衡的原因。

解：由裝置圖可知，蠟燭和堿石灰處于開(kāi)放的空間，燃燒生成的熱的二氧化碳和水蒸氣被堿石灰全部吸收，而先前并沒(méi)有稱量反應(yīng)掉的氧氣的質(zhì)量，所以導(dǎo)致天平的左盤(pán)就會(huì)逐漸下沉。

故答案為：（1）左盤(pán)（2）根據(jù)質(zhì)量守恒定律，參加化學(xué)反應(yīng)的各物質(zhì)的質(zhì)量總和等于生成的各物質(zhì)的質(zhì) 量總和，該反應(yīng)反應(yīng)物是氣體，先前稱重沒(méi)有被測(cè)量，所以天平失衡，且左側(cè)重。

17（2009大連）地球是一個(gè)巨大的能源倉(cāng)庫(kù)，不僅蘊(yùn)藏著煤、石油、天然氣等能源，還蘊(yùn)藏著豐富的可再生的地?zé)崮?。地?zé)崮苁侨祟悮v史上開(kāi)辟的又一新能源，它可直接用于居室取暖、供熱和工業(yè)發(fā)電等。從環(huán)境、能源等方面具體說(shuō)明使用地?zé)崮艿膶?shí)際意義。（答出三條）

解：現(xiàn)今地球上的三大化石燃料--煤、石油、天然氣即將耗盡，地?zé)崮芸稍偕?，使用地?zé)崮苣芄?jié)約化石燃料，解決目前的能源危機(jī)問(wèn)題，且使用地?zé)崮懿粫?huì)生成一氧化碳、二氧化硫、二氧化氮等有毒氣體，可防止環(huán)境污染，除此之外，地?zé)崮艿某杀据^低，可推廣應(yīng)用。

故答案為：可以節(jié)約化石燃料；可以減少對(duì)環(huán)境的污染；使用成本低，經(jīng)濟(jì)效益高。（其他答案合理也可）

18（2009?大連）城市中的生活用水是經(jīng)自來(lái)水廠凈化處理過(guò)的。（1）除去水中不溶性雜質(zhì)可采用什么方法？

（2）飲用被病菌污染的水會(huì)感染疾病，向水中通入氯氣可殺死病菌。氯氣能跟水發(fā)生如下反應(yīng)：Cl2+H2O═HCl+HClO（次氯酸），使水顯酸性，腐蝕金屬管道。為了使自來(lái)水廠輸出水的pH約為8，輸出前通常向水中加入熟石灰，寫(xiě)出可能發(fā)生反應(yīng)的化學(xué)方程式。

解：過(guò)濾可將水中不溶性雜質(zhì)與水分離而除去，故除去水中不溶性雜質(zhì)可采用過(guò)濾的方法； 氯氣能跟水反應(yīng)生成的HCl、HClO都屬于酸，與堿類物質(zhì)氫氧化鈣發(fā)生中和反應(yīng)生成氯化鈣、次氯酸鈣和水，反應(yīng)的化學(xué)方程式分別為：2HCl+Ca（OH）2═CaCl2+2H2O和2HClO+Ca（OH）2═Ca（ClO）2+2H2O。

故答案為：（1）過(guò)濾；（2）2HCl+Ca（OH）2═CaCl2+2H2O；2HClO+Ca(OH)2═Ca（ClO）2+2H2O。

19.（2009?大連）用微粒的觀點(diǎn)解釋下列事實(shí)。

（1）向氣象氣球中充入氫氣，隨著氣球的上升，其體積逐漸變大。

（2）貯存氣體的容器必須具備的條件之一是不滲漏，而貯存氫氣的容器要達(dá)到這一條件卻非常困難。

解：（1）氫分子間有間隔，隨著氣球的上升，壓強(qiáng)的逐漸減小，氫分子的間隔逐漸變大，所以其體積逐漸變大；

（2）相比其他氣體，氫分子的體積、質(zhì)量均最小，運(yùn)動(dòng)速率最快，所以氫氣極易通過(guò)各種很小的空隙散逸。

20.（2009?大連）由緩慢氧化引起的自發(fā)燃燒叫自燃。秸稈、柴草、煤等在一定條件下都能發(fā)生自燃的現(xiàn)象。

（1）解釋某柴草堆發(fā)生自燃的原因。

（2）對(duì)如何存放可燃物以防止其發(fā)生自燃提出兩條建議。

解：（1）因柴草堆長(zhǎng)期放置，會(huì)發(fā)生緩慢氧化釋放出能量，能量不斷累積，使溫度升高，達(dá)到草堆燃燒需要的著火點(diǎn)，則柴草堆發(fā)生自燃，答：草堆內(nèi)部由于緩慢氧化產(chǎn)生的熱量累積起來(lái)，溫度升高達(dá)到草堆的著火點(diǎn)，從而引起自燃；（2）因可燃物燃燒需要與氧氣接觸，溫度達(dá)到可燃物的著火點(diǎn)，則在通風(fēng)的情況下減少緩慢氧化產(chǎn)生的熱量，或在低溫下保存都可防止自燃的發(fā)生，故答案為：經(jīng)常通風(fēng)，保持空氣流通；低溫存放。21.（2008大連）據(jù)報(bào)道：近日，一輛行駛在某鄉(xiāng)村國(guó)道上運(yùn)鎂粉的罐車起火。由于鎂粉遇熱水反應(yīng)生成氫氣，因此，消防官兵采用覆蓋沙土的方法將火撲滅。

（1）鎂粉燃燒通常需要什么條件？（2）覆蓋沙土滅火的原理是什么？（3）解釋鎂粉著火不能用水滅火的原因。

解：（1）鎂粉燃燒通常需要的條件：溫度達(dá)到著火點(diǎn)、與氧氣（或空氣）接觸；

（2）覆蓋沙土滅火的原理是：隔絕空氣（或氧氣）；

（3）解釋鎂粉著火不能用水滅火的原因：鎂粉遇熱水反應(yīng)生成氫氣，氫氣會(huì)繼續(xù)燃燒，可能爆炸。

故答為：（1）與氧氣接觸，且溫度達(dá)到著火點(diǎn)；（2）隔絕空氣（或氧氣）；（3）鎂能與水反應(yīng)生成能夠燃燒的氣體氫氣。

22.（2008?大連）高錳酸鉀中氧元素的質(zhì)量分?jǐn)?shù)與氯酸鉀中氧元素的質(zhì)量分?jǐn)?shù)相差很小，但等質(zhì)量的高錳酸鉀和氯酸鉀（另加少量二氧化錳作催化劑）分別加熱，充分反應(yīng)后，高錳酸鉀分解產(chǎn)生的氧氣的質(zhì)量卻遠(yuǎn)遠(yuǎn)小于氯酸鉀分解產(chǎn)生的氧氣的質(zhì)量。運(yùn)用所學(xué)知識(shí)解釋原因。

解：由化學(xué)方程式不難看出：高錳酸鉀中的氧元素只有部分轉(zhuǎn)化為氧氣單質(zhì)，氯酸鉀中的氧元素全部轉(zhuǎn)化為氧氣。故等質(zhì)量的高錳酸鉀和氯酸鉀分別加熱，充分反應(yīng)后，高錳酸鉀分解產(chǎn)生氧氣的質(zhì)量卻遠(yuǎn)遠(yuǎn)小于氯酸鉀分解產(chǎn)生氧氣的質(zhì)量。

故答為：高錳酸鉀完全分解生成K2MnO4和MnO2中含有一部分氧元素，所以高錳酸鉀中的氧元素并沒(méi)有完全轉(zhuǎn)化成氧氣；而氯酸鉀分解生成的KCl中不含氧元素，可見(jiàn)氯酸鉀中的氧元素完全轉(zhuǎn)化為氧氣了。所以等質(zhì)量的氯酸鉀比高錳酸鉀放出的氧氣多。

23.（2008大連）普通塑料是由石油產(chǎn)品加工后得到的，而玉米塑料是以存放1～2年陳化玉米等富含淀粉的農(nóng)作物為原料生產(chǎn)的。玉米塑料除了具備普通塑料同樣的物理性能外，其廢棄物還能自然降解為水和二氧化碳。根據(jù)以上信息回答：

（1）從不同角度，寫(xiě)出使用玉米塑料的兩條優(yōu)點(diǎn)，并說(shuō)明理由

（2）玉米塑料的生產(chǎn)和使用經(jīng)歷了“玉米生長(zhǎng)

合成塑料

廢棄物降解

玉米在生長(zhǎng)?”的過(guò)程，在這一過(guò)程中，實(shí)現(xiàn)了物質(zhì)的循環(huán)。簡(jiǎn)述二氧化碳是如何參與循環(huán)的。解：（1）玉米陳化已不能再食用；玉米不但具有普通塑料物理性質(zhì)，而且具有普通塑料所不能降解等優(yōu)點(diǎn)，從這兩個(gè)方面分析。

故答案為：①合理利用資源，變廢為寶，理由是陳化玉米人畜不能食用，丟棄會(huì)造成資源浪費(fèi)，②保護(hù)環(huán)境，理由是玉米塑料易降解，能夠防止土壤污染。

（2）玉米是經(jīng)過(guò)光合作用合成有機(jī)物，又通過(guò)降解完成分解變成二氧化碳和水。

故答案為：玉米生長(zhǎng)時(shí)，通過(guò)光合作用吸收二氧化碳和水，合成淀粉；玉米塑料廢棄物在空氣中降解為二氧化碳和水。

24.（2008?大連）某鹽湖中含有氯化鈉和硫酸鎂等物質(zhì)，隨著溫度的變化，該鹽湖中會(huì)析出不同的物質(zhì)。冬季，當(dāng)水溫降至10℃左右，開(kāi)始析出氯化鈉晶體；當(dāng)水溫降至0℃左右，開(kāi)始析出硫酸鎂 晶體。

（1）根據(jù)如圖氯化鈉和硫酸鎂的溶解度曲線可知，10℃時(shí)硫酸鎂的溶解度比氯化鈉的溶解度小，為什么硫酸鎂沒(méi)有析出？

（2）根據(jù)上述現(xiàn)象，說(shuō)明隨著溫度的變化，物質(zhì)結(jié)晶與哪些因素有關(guān)。

解：（1）在10℃時(shí)硫酸鎂的溶解度比氯化鈉的溶解度小，但硫酸鎂并沒(méi)有結(jié)晶析出，說(shuō)明在溶液中硫酸鎂沒(méi)有達(dá)到飽和，說(shuō)明在溶液中硫酸鎂的質(zhì)量分?jǐn)?shù)較小，故答案為：一是鹽湖中含氯化鈉的質(zhì)量分?jǐn)?shù)大，二是氯化鈉的溶解度隨溫度變化不大當(dāng)溫度降低時(shí)氯化鈉首先達(dá)到飽和繼續(xù)降溫會(huì)析出氯化鈉而此時(shí)硫酸鎂還沒(méi)有達(dá)到飽和，當(dāng)溫度降低到0℃時(shí)，氯化鈉的溶解度比硫酸鎂溶解度大，此時(shí)硫酸鎂開(kāi)始析出。

（2）根據(jù)上述現(xiàn)象可知，溶液中溶質(zhì)的結(jié)晶析出不僅和物質(zhì)的溶解度有關(guān)，還和溶液中溶質(zhì)的質(zhì)量分?jǐn)?shù)有關(guān)，故答案為：物質(zhì)的溶解度、溶質(zhì)的質(zhì)量分?jǐn)?shù)的大小。

25.（2006?大連）某干洗劑的主要成分是四氯乙烯（C2Cl4，它是一種易揮發(fā)、可致癌的有毒物質(zhì)。

（1）干洗后的衣服剛?cè)』貢r(shí)，往往需要掛在室外通風(fēng)處一段時(shí)間。請(qǐng)用微粒的觀點(diǎn)解釋這樣做的原因。

（2）有些干洗店用裝有活性炭的新款干洗機(jī)取代舊款的干洗機(jī)，可將有毒物質(zhì)大約降至原來(lái)的1/30。這一做法利用了活性炭的性。

解：（1）因?yàn)樗穆然际怯卸镜奈镔|(zhì)，為了減小它對(duì)人體造成的危害，利用其揮發(fā)性，讓有毒的分子擴(kuò)散到空氣中。

（2）活性炭具有疏松多孔的結(jié)構(gòu)，能吸附一些色素和有害氣體。

故答案為：（1）物質(zhì)由微粒（分子）構(gòu)成，微粒（分子）是不斷運(yùn)動(dòng)的，將于洗后的衣服掛在室外的通風(fēng)處，四氧乙烯的微粒（分子）會(huì)擴(kuò)散到空氣中，減少殘存的四氯乙烯對(duì)人體的危害。（2）吸附。

26.（2006?大連）在一次失火后的現(xiàn)場(chǎng)處理中，消防人員發(fā)現(xiàn)某種易燃物質(zhì)保存了下來(lái)。分析原因，得知該物質(zhì)中添加了一種阻燃劑。當(dāng)火情出現(xiàn)時(shí)，這種阻燃劑發(fā)生化學(xué)反應(yīng)，吸收熱量，生成的產(chǎn)物覆蓋在易燃物質(zhì)表面。這些都起到了阻止該物質(zhì)燃燒的作用。（1）從燃燒條件分析，這種易燃物質(zhì)沒(méi)有燃燒的原因。

（2）推測(cè)這種阻燃劑發(fā)生化學(xué)反應(yīng)后，生成的產(chǎn)物應(yīng)具有的化學(xué)性質(zhì)（寫(xiě)出一點(diǎn)即可）：

解：（1）阻燃劑發(fā)生化學(xué)反應(yīng)吸收熱量，降低了易燃物質(zhì)周圍的溫度，使溫度達(dá)不到該易燃物質(zhì)的著火點(diǎn)；阻燃劑發(fā)生反應(yīng)生成的產(chǎn)物覆蓋在該易燃物質(zhì)的表面，隔絕了氧氣。（2）因?yàn)槭亲枞紕?，所以生成的產(chǎn)物應(yīng)具有的化學(xué)性質(zhì)是：不燃燒、不支持燃燒。故填：不燃燒、不支持燃燒。

27.（2006大連）33。20世紀(jì)80年代，有人曾制造了一個(gè)“水變油”的騙局：

（1）騙局制造者稱：只要在一盆清水中加入一些“神秘”的液體作催化劑，清水就可以變成能燃燒的汽油。

請(qǐng)用學(xué)過(guò)的化學(xué)知識(shí)解釋：水不能變成汽油。

（2）騙局制造者的手段是在水中加入一定量的汽油，再加入輔料黑色肥皂，使原本不相溶的水和汽油混合在一起，好像是變成了黑糊糊的油，并稱之為“水基燃料”。這里黑色肥皂起 作用，而使細(xì)小油滴均勻懸浮在水中。

（3）在進(jìn)行“水基燃料”燃燒演示時(shí)，由于燃燒后沒(méi)有水留下，所以許多人認(rèn)為其中的水已全部轉(zhuǎn)變?yōu)槟苋紵钠?，從而受到蒙蔽。?qǐng)解釋為什么“水基燃料”燃燒后沒(méi)有水留下。

解：（1）根據(jù)質(zhì)量守恒定律可知，化學(xué)反應(yīng)前后元素的種類不變；水由氫、氧元素組成，汽油主要由碳、氫元素組成，水中不含碳元素，所以水不能變成汽油。故答案為：根據(jù)質(zhì)量守恒定律可知，化學(xué)反應(yīng)前后元素的種類不變；水由氫、氧元素組成，汽油主要由碳、氫元素組成，水中不含碳元素，所以水不能變成汽油。

（2）乳化作用是將一種液體分散到第二種不相溶的液體中去的過(guò)程，最大的一類的乳化劑是肥皂、去污粉和其他化合物。汽油本身不會(huì)和水互溶，加入黑色肥皂，汽油和水混合在一起，所以黑色肥皂的作用就是乳化作用，故答案為：乳化。

（3）汽油燃燒放出大量的熱量，這樣水就會(huì)逐漸蒸發(fā)，因此最后沒(méi)有任何物質(zhì)剩余，故答案為：汽油燃燒時(shí)產(chǎn)生熱量，使水分蒸發(fā)。

28.（2004?大連）放置在空氣中的鋁制品和黃金制品，都不易腐蝕。請(qǐng)你分別說(shuō)明原因。

解：鋁的化學(xué)性質(zhì)較活潑，但鋁制品易在空氣中形成致密的氧化膜，起到保護(hù)作用，黃金則是化學(xué)性質(zhì)很穩(wěn)定，因此都不易腐蝕。

故答案為：常溫下，鋁在空氣中跟氧氣反應(yīng)，表面生成一層致密的氧化膜；黃金的化學(xué)性質(zhì)不活潑。

29.（2004?大連）成語(yǔ)“點(diǎn)石成金”，本意為古代方士的一種法術(shù)，即能使石頭變成黃金，現(xiàn)比喻能化腐朽為神奇，有人說(shuō)他能把石灰石變成黃金，請(qǐng)你用化學(xué)知識(shí)說(shuō)明石灰石不能變成黃金的道理。

解：根據(jù)質(zhì)量守恒定律可知，化學(xué)反應(yīng)前后元素的種類不變。石灰石的主要成分是碳酸鈣，它是由鈣元素、碳元素、氧元素組成的，黃金是由金元素組成的。因此，石灰石是不可能變成黃金的。故答案為：根據(jù)化學(xué)反應(yīng)前后元素種類不變的原理，可知石灰石是不可能變?yōu)辄S金的。30.（2003?大連）（4分）早在17世紀(jì)，質(zhì)量守恒定律發(fā)現(xiàn)之前，英國(guó)化學(xué)家玻義耳曾經(jīng)做過(guò)一個(gè)實(shí)驗(yàn)：在密閉的容器中燃燒金屬時(shí)，得到了金屬灰，然后打開(kāi)容器蓋，稱量金屬灰的質(zhì)量，發(fā)現(xiàn)比原來(lái)金屬質(zhì)量增加了。

（1）試解釋金屬灰質(zhì)量比原金屬質(zhì)量增加的原因。

（2）由于玻義耳稱量方法上的原因，他錯(cuò)過(guò)了發(fā)現(xiàn)質(zhì)量守恒定律的機(jī)會(huì)。請(qǐng)你改進(jìn)他的稱量方法，以驗(yàn)證質(zhì)量守恒定律。

解：（1）金屬燃燒是金屬和氧氣發(fā)生化合反應(yīng)，生成金屬氧化物。根據(jù)質(zhì)量守恒定律可知，參加反應(yīng)的金屬與氧氣的質(zhì)量之和等于生成的金屬氧化物的質(zhì)量。生成的金屬灰是金屬氧化物，所以金屬灰的質(zhì)量比原來(lái)金屬的質(zhì)量增加了。（2）不打開(kāi)容器蓋，分別稱量反應(yīng)前后密閉容器的質(zhì)量。

31.（2003?大連）（4分）氮?dú)饪捎米魉谋Ｗo(hù)氣，紅磷可用于制造煙幕彈。請(qǐng)分別說(shuō)明原因，并寫(xiě)出有關(guān)反應(yīng)的文字表達(dá)式。

解：氮?dú)獾幕瘜W(xué)性質(zhì)不活潑，不易與其他物質(zhì)反應(yīng)，可用作水果的保護(hù)氣。

紅磷在空氣中燃燒產(chǎn)生大量的白煙，可用于制造煙幕彈，反應(yīng)的文字表達(dá)式為：磷+氧氣五氧化二磷。

故答案為：氮?dú)獾幕瘜W(xué)性質(zhì)不活潑；紅磷在空氣中燃燒產(chǎn)生大量的白煙；磷+氧氣化二磷。

32。（2003?大連）（4分）在加壓的情況下，可以將25000L石油氣裝入容積為24L的鋼瓶中。請(qǐng)從微觀的角度加以解釋。

解：分子間有間隔，氣體分子間的間隔相對(duì)較大，氣體受壓時(shí)，迫使氣體分子間距離縮小，因此其體積也相應(yīng)縮小。

五氧