【西安】2016-2017益新中学初三三模
西安益新中学初三化学上册期末模拟考试化学试卷

西安益新中学上册期末模拟考试化学试卷一、九年级化学上册选择题1.在一个密闭容器内有X、Y、Z、Q四种物质,在一定条件下充分反应,测得反应前后各物质的质量如下表所示,下列推理正确的是()物质X Y Z Q反应前质量(g)1810221反应后质量(g)01215待测A.反应物是X和Y,生成物是Z和QB.该反应是化合反应,Q可能是催化剂C.Y、Z两种物质中元素种类一定与X中元素种类相同D.反应后Q的质量为24g2.蜡烛(足量)在如图甲图密闭装置内燃烧至熄灭,用仪器测出这一过程中瓶内氧气含量的变化,如图乙所示。
下列判断正确的是()A.蜡烛熄灭后瓶内只剩二氧化碳气体B.蜡烛熄灭时并没有消耗装置内所有的氧气C.蜡烛燃烧前装置内只有氧气D.蜡烛燃烧能将密闭装置中的氧气耗尽3.下列4 个坐标图分别表示4 个实验过程中某些质量的变化,其中正确的是()A.等体积、等质量分数的双氧水溶液分解B.木炭在盛有氧气的密闭容器内燃烧C.加热一定质量的高锰酸钾固体D.镁条在空气中燃烧4.将一定质量的A、B、C、D四种物质放入一密闭容器中,在一定条件下反应一段时间后,测得反应后各物质的质量如下表:物质A B C D反应前的质量/g410125反应后的质量/g待测21109若A的相对分子质量为n,D的相对分子质量为2n,则下列说法正确的是()A.该反应中生成B与C的质量比为21:10B.该反应不遵循质量守恒定律C.该反应中A与D的化学计量数之比为1:2D.该反应是分解反应5.下列叙述与对应的坐标图表示正确的是()A.向硝酸钾的饱和溶液中加入氯化钠B.将相同质量的Zn粉和Mg粉分别加入足量的稀盐酸中C.水的电解D.盐酸和氯化铁混合溶液中加入过量的氢氧化钠溶液6.已知某气体由H2、CO2、CO、CH4中的两种组成,为确定其成分进行了下面的实验:①将气体通过澄清的石灰水,未出现浑浊现象;②将气体通过灼热的氧化铜,有红色固体生成;③点燃气体,用蘸有澄清石灰水的烧杯罩住火焰,烧杯壁上有浑浊出现。
2016-2017陕西省西安市益新中学初三上期中试卷

九年级英语试题(卷)(人教版)第Ⅰ卷(选择题共65分)笔试部分Ⅲ、单项选择(共10小题,计10分)本题共有10个小题,请从每个小题的四个选项中,选出一个最佳答案.21. Many __________ visited the Great Wall. They all come from __________ .A. Germen; GermanyB. Germany; GermanC. Germans; GermanyD. Germany; Germen22. David is __________ late for class though he lives far from school.A. oftenB. seldomC. sometimesD. always23. —Tom, what do you think is the secret __________ writing in English?—__________ reading lots of English activities, you can improve it a lot.A. with; AboutB. to; AboutC. with; ByD. to; By24. —How nice the fish __________ !—Really? I am sure you‟ll like it better if you try some.A. smellsB. feelsC. tastesD. sounds25. You cannot avoid __________ her if you work in the same office.A. to meetB. meetingC. meetD. to meeting26. —Michael, you have __________ a lot of weight recently.—Yes, I was 62 kg a year ago, but now I‟m 73 kg.A. put onB. thrown awayC. washed awayD. dressed up27. Artemisinin __________ by Tu Youyou, a great Chinese scientist.A. was discoveredB. discoveredC. has discoveredD. is discovered28. The oven is made __________ Shanghai, It is used to __________ food.A. from; cookB. by; cookingC. in; cookD. of; cooking29. Rose __________ tell her mother that she didn‟t pass the exam.A. dare not toB. doesn‟t dare toC. dare don‟tD. don‟t dare30. —Show me the map, please. I wonder __________ .—Lo ok, it‟s here, in the east of China, near Taiwan Province.A. where is Diaoyu IslandB. where Diaoyu Island isC. what is Diaoyu Island likeD. what Diaoyu Island is likeⅣ、完形填空(共10小题,计10分)阅读下面一篇短文,理解大意,然后从各小题的四个选项中选出一个最佳答案,使短文连贯完整.Last Sunday, I met an old friend in the street. We haven‟t seen each other 31 three years. She has 32 a lot. She 33 very fat and always 34 a pair of glasses. But now, she is very thin and the glasses are gone. She 35 so beautiful with big eyes and long, blond hair —it used to be short and brown. She used to be very shy and was 36 of speaking in class. Now she is outgoing and she told me she 37 her school band and played 38 guitar. She said she hoped I could go to see her performance 39 . She looks so confident and I know she isn‟t what she used to be 40 .31.A. in B. for C. during D. with32.A. changed B. been changed C. turned D. grown33.A. used to B. was used to be C. used to be D. was used to being34.A. put on B. wore C. wears D. dressed35.A. seems B. was like C. looks D. looked36.A. afraid B. proud C. ready D. tired37.A. attended B. joined in C. joins D. joined38.A. the B. a C. / D. some39.A. some days B. sometimes C. some day D. some time40.A. no more B. no longer C. not any more D. any moreⅤ、阅读理解(共15小题,计20分)第一节:阅读下面一篇短文,判断下列句子是否符合短文内容,符合的用“A”表示,不符合的用“B”表示.(共5小题,计5分)AAt this time of the year, when you look up at the sky, some “man-made birds” may catch your eyes. These “birds” are col orful kites.Kites were invented in China. In the beginning, they were made of wood and bamboo. People used them to pass messages or as warning signals (警告标志) during the wartime.Later,paper kites became popular and people flew kites to get rid of (除去) bad luck and bless(保佑) themselves.Today, the custom is still alive there are traditional patterns (图案) in some kites, such as thebat standing for blessing.However, modem kites come in different shapes and patterns. The largest kite in the world is a big ……octopus” It‟s 1,500 square mete rs, which is as big as three basketball courts(球场). A kite team from Tianjin made it in three months.Kite flying is an enjoyable sight in the sky. In China, the best time to enjoy colorful kites in during the Weifang International Kite Festival in April. The festival has competitions for kiteflying skills and new styles of kites.Kite flying is also a healthy sport. It is good for your neck and eyes. When looking at the flying kites in the sky, your neck and eyes become relaxed.41. The “man-made birds” that you see in the sky are kites.42. During the wartime, kites were mainly used to pass massages or rid bad luck.43. People flied kites later on because they wanted to bless themselves.44. The big “octopus” kits is 1,500 square meters, which is bigger than three basketball courts.45. The Weifang International Kite Festival have competitions for kite-flying skills and new styleof kites.第二节:阅读B、C、D三部分内容,从各小题的四个选项中选出能回答所提问题或完成所给句子的最佳答案.(共10小题,计15分)Bpartly made from plants and can be recycled (can help to deal with the problem of climate (green and environment-friendly , and as bright ascostswater?invention can amplify (46. Which of the following statements is TRUE about the “PlantBottle”A. The bottle is completely made of plants.B. It was a product of the Coca Cola Company.C. It costs much money.D. People can‟t recycle it.47. The new light bulb __________ .A. is brighter than the old onesB. isn‟t good for the environmentC. can last at least 25 yearsD. can last less than 25 years48. The Water Talky was invented by __________ .A. German scientistsB. a young childC. a UK companyD. some swimmersCDo you like telling jokes in your English study? Jokes can make your words colourful and interesting. If you make people laugh, you can know that people are interested in your topic.In order to get jokes, you can watch comedies or talk shows on TV. When you hear David Letterman‟s jokes in his programme, you‟d better write them d own. Then you can have more jokes to tell when you talk with others. If your English is good enough, you can also write your own jokes to tell at a party or to break the ice before a speech.How to make your jokes more interesting? Not all the English words sound funny. Some English words sound funny by themselves, while others can get a laugh only in phrases and sentences. You have to choose. Different people may have different feelings on a joke. So don‟t be sad if others don‟t laugh after you tell a joke. After all, telling English jokes is just a way to help you with your English study.49.If people laughed after you told a joke, they might be __________ your topic.A. bored withB. sad aboutC. interested inD. good at50. From the passage, we can guess that David Letterman may be a(n) __________ .A. movie actorB. English writerC. language learnerD. host (主持人) of a talk show51.Which of the following is TRUE according to the passage?A. Almost all the English words sound funny.B. Your words can‟t be interesting without jokes.C. You can write your own jokes to get a laugh.D. People always like the same jokes when they listen to a talk show.52. What is the best title for the passage?A. Colouring Your Life.B. Making Friends at Parties.C. Famous English Jokes.D. Learning English by Telling Jokes.D“How are you?” is a nice question. It‟s a friendly way that people in the United States greet each other, but “How are you?” is also a very unusual question. It‟s a question that often doesn‟t have an answer. Theperson who asks “How are you?” hopes to hear the answer “Fine”, even if the Derson‟s friend isn‟t fine. The reason is that “How are you?” isn‟t really a question and “Fine”isn‟t really an answer. They are simply other ways of saying “Hello” or “Hi !”.Sometimes, people also don‟t say exactly what they mean. For example, when someone asks “Do you agree?” the other person might be thinking, “No, I disagree. I think you‟re wrong.” But it isn‟t very polite to disagree so strongly, so the other person might say “I‟m not sure.” It‟s a nicer way to say that you don‟t agree with someone.People also don‟t say exactly what they are thinking when they finish talking with other people. For example, many talks over the phone finish when one person says “I have to go now.”Often, the person who wants to hang up gives an excuse: “Someone‟s at the door.”“Something isburning on the stove(火炉).” The excuses might be real, or it might not. Perhaps the person who wants to hang up simply doesn‟t want to talkany more, but it isn‟t polite to say that. The excuse is more polite, and it doesn‟t hurt the other person.Whether they are greeting each other, talking about an idea, or finishing a talk, people don‟t say exactly what they are thinking. It‟s an important way that people try to be nice to each other, and it‟s part of thegame of language.53. When a person in the United States asks “How are you?”, he or she wants to hear“__________”.A. How are you?B. Hello.C. I don‟t know.D. Fine.54. A polite way to finish a talk is to say “__________”.A. You have to go nowB. I want to hang upC. I have to go nowD. I don‟t want to talk55. When a person says “I have to go now. Someone‟s at the door”, the person may be__________ .A. giving an excuseB. hurting someone‟s feelingC. talking to a person at the doorD. going to another place第Ⅱ卷(非选择题共55分)Ⅵ、完成句子:根据所给汉语意思,用单词或短语完成下列英文句子.(共5小题,计10分) 56.我们被分成两组.We _________________________________________ two groups.57.你知道如何应对她的害羞吗?Do you know how to _____________________ her shyness?58.令我吃惊的是,他一直在浪费时间._____________________________ , he is wasting his time all the time.59.看!孩子们正在为聚会摆放水果和甜点.Look! The children are _________ the fruits and desserts for the party.60.在英国,女王毫无疑问是最高统治者.In England the supreme ruler is the queen _________________ .Ⅶ、短文填空(共10小题,计10分)用方框中所给单词的适当形式填空,使短文完整正确,每词限用一次,每空只填一个单词.I was a student of yours in Grade Seven, and I hope you can still 61 me. I am writing this letter to tell you that the school year with you was important and special to me. It made 62 in it all the time.You know I 63 to be quiet in class, And you die something that changed my life a lot. You see, all through my first year at school. I 64 to read. Books were very boring for me. I‟ll never forget the first day of Grade Seven.On that day, you took out a book and 65 to read a story to us. It 66 that your voice changed with the people in the story, and you drew pictures in my mind as you read aloud.From then on, I made a 67 to do the reading well. I will never give up 68 in my life!When I picked up a book read it 69 , I found that I could make the words interesting, too. Now I love reading! Thank you for 70 the world of books for me.Yours,AmyⅧ、任务型阅读(共5小题,计10分)阅读下面短文,根据短文内容,完成下列各题.Every year there is the Spring Festival in China. Usually it is in January or February. It‟s th e most important festival in China. So before it comes, everyone has to prepare things. They buy b eef, pork, chicken, fruit and many other things. And they often make a special kind of food calle d “dumplings”. It means “come together” in Chinese. On the day before the festival, parents buy n ew clothes for their children and children also buy presents for their parents. On the festival eve, al l the family members come back to their home. This is a happy moment. They sing, dance and pla y cards. When they enjoy the meal, they give each other the best wishes for the coming year. The y all have a good time.71. Which is the most important festival in China?The most important festival is ________ in China.72. Then do the Chinese usually have their Spring Festival?They usually have their Spring Festival in ____________ .73. What‟s the special kind of food for the Spring Festival in China?The special kind of food is _______________ .74. What does the food“dumplings” mean?It means “______________” .75. When they are having dinner on the festival eve, What do the Chinese do?They ___________ when they are having dinner on the festival eve.Ⅸ、补全对话(共10小题,计10分)A)根据对话内容,将方框中符合对话情境的语句抄写在对话空白处,使对话恢复完整.选项中有两项是多余的.A: Hello, Mrs. Smith! Welcome to my house.B: Thanks for your invitation, Mrs. King.A: 76. ______________________B: Sure.A: 77. ______________________B: Some Pu‟er would be great, thanks.A: Sure. I just got some from my Chinese friend. He is from Yunnan and he bought it in a shop there.B: Oh, 78. ___________________A: You‟re right. Chinese tea is drunk by people all over the world.B: Wow, this cup is beautiful and a little heavy. 79. _________________________A: It is made of silver. I have many tea sets like this. 80. ________________________B: Sounds like a great hobby.B)根据对话的情境,在每个空白处填入一个适当的语句,使对话恢复完整.A: Li Lei, what are you going to do this new term?B: I‟m going to improve my English. 81. _________________________ .A: You must read aloud to practice it.B: OK. 82. _________________________?A: Listening to more tapes will help you improve your listening.B: That‟s good idea. 83. ___________________________?A: You should read books and newspapers in English and try to guess the meanings of the new words.B: Can I write down the new words in my notebook?A: 84. ____________________________ . It can help you remember the new words.B: OK, I‟ll follow your advice. Thanks a lot.A: You‟re welcome. 85. _______________________ .Ⅹ、书面表达(共1题,计15分)初中生活中,你有些什么改变?你是怎样改变的?请写一篇不少于70词的英语小短文,描述你发生的变化,写作内容可包括:兴趣爱好、行为习惯、学习习惯等方面.要求:1.语言流畅、书写规范、卷面整洁.文中不得使用你的真实姓名和校名.2.开头已给出,但不计入总词数.How time flies, two years has quickly passed, and I have changed a lot during the two years, _______________________________________________________________________________ _______________________________________________________________________________ _______________________________________________________________________________。
陕西省西安市中考化学三模试卷(含解析)

是( )
A.化学反应前后,原子核分子的总数都不变,但分子的种类一定改变 B.氨气中氮、氢元素的质量比为 1: 3 C.该反应属于复分解反应 D.该反应生成的氧化物的相对分子质量为 18
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5.对于下列几种化学符号,有关说法正确的是(
①H
② Fe2+
③Cu
④P2O5
) ⑤ Fe3+⑥ NaCl.
个.
( 2)请写出其中可用于除铁锈的化学反应方程式
( 3)若 A 和 E 牵手,则以上反应中不包含基本反应类型中的
.
11.人类的日常生活和工农业生产离不开水,请回答: Ⅰ.用如图所示的净水器处理浑浊的河水,(净水器中有石英砂、活性炭、纱布等) ,下列分析正确的是 A、净化后的河水属于混合物 B、该净水器能将硬水变为软水 C、该净水器能杀菌消毒 D、用活性炭可以除去水中的色素和异味. Ⅱ.海水占了全球水资源的 97%,海水资源的开发和利用具有非常广阔的前景,海水中含有 大量的 NaCl,可用于制备 实验,其流程如图:
分类法 根据组成物质的元素种类,将纯净物分为单质和化合物
B
类比法 根据金属铝能与稀盐酸反应,推测金属铜也能与稀盐酸反应
C
归纳法 根据氢氧化钠、氢氧化钙等物质的化学性质,归纳出碱的通性
D
实验法 用磷做“测定空气中氧气含量”的实验
A.A、 B. B、 C. C、 D. D、 【分析】 A、根据物质的分类方法解答;
D.维生素在人体内可以起到调节新陈代谢、预防疾病和维持身体健康的重要作用
【分析】 根据化学元素与人体健康、化学变化的概念以及能量的转化进行分析解答即可.
【解答】 解: A、钙是人体必需的元素,要注意合理摄入,摄入不足或过量均不利于人体健
2016-2017陕西省西安市益新中学初三上第二次月考试卷

2016-2017学年度第一学期2017届(初三)第二次月考英语试题第Ⅰ卷选择题(65分)笔试部分Ⅲ、单项选择(共10小题,计10分)本题共有10个小题,请从每个小题的四个选项中,选出一个最佳答案.21. All the students like the teachers __________ can understand them well.A. WhoB. whichC. whatD. whom22. Mr Wang often says to us, “__________ is very im portant for language learning.”A. Read aloudB. Reading aloudC. Reading loudlyD. Read loud23. —Lily, can you tell me __________ ?—Paul? I haven‟t seen him for years. He used to be a shy and quiet boy.A. what is Paul likeB. what Paul is likeC. what does Paul likeD. what Paul likes24. I took her bag instead of mine __________ .A. for mistakeB. by accidentC. by mistakeD. by chance25.The story books for kids are really awful. They are __________ interesting __________exciting.A. either, orB. neither, norC. both; andD. not only; but also26. Don‟t make much __________ when you study in groups.A. noiseB. noisesC. noisyD. sound27. —Food safety is very important.—So some laws(法律) must __________ stop people from polluting food.A. makeB. be made toC. be madeD. make to28. The boy behaved so __________ on the subway that he was told to be __________A. polite; impolitelyB. impolite; politelyC. impolitely; politeD. polite; politely29. What does Tony like best __________ the Chinese Spring Festival?A. withB. forC. aboutD. in30. I found __________ very easy to learn English well if you create an interest in what you learn.A. whatB. thatC. itD. thisⅣ、完形填空(共10小题,计10分)阅读下面一篇短文,理解大意,然后从各小题的四个选项中选出一个最佳答案,使短文连贯完整.Tony and his friends found a strange old box filled with candies and 31 treasure map. They thought they might have belonged to Stickybeard, a famous candy-loving pirate (海盗) who hid a lot of treasure in a secret place. They were very 32 and started to 33 the treasure.They 34 the map carefully and found another small box. In the box, they found a few candies, the letter 35 and another map. The new map led them to a big tree where they found another box with some candies, a new map, and a big letter O. They went on and found 36 two boxes with the letters V and E. However, on the last map they found that was a puzzle (谜).They spend a long time discussing about the meaning 37 the puzzle. Finally , Alex, one of Tony‟s 38 , found the answer, “The puzzle wants us to put the letterswehave collected beside our father and mother.” He added, “39 the answer to the puzzle must be …love your parents‟.”The great treasure Stickybeardor someone else left the kids was a great piece of 40 —love your parents. From then on, Tony and his friends loved their parents more than ever. ( )31. A. a B. an C. the D. /( )32. A. tired B. sad C. excited D. nervous( )33. A. look after B. look at C. look for D. look through( )34. A. point B. read C. drew D. forgot( )35. A. M B. P C. Y D. L( )36. A. another B. other C. the other D. others( )37. A. to B. for C. with D. of( )38. A. friend B. parents C. friends D. puzzles( )39. A. If B. So C. Or D. But( )40. A. paper B. advice C. land D. newsⅤ、阅读理解(共15小题,计20分)第一节:阅读下面一篇短文,判断下列句子是否符合短文内容,符合的用“A”表示,不符合的用“B”表示.(共5小题,计5分)AI used to travel by air very often when I was a boy. My parents used to live in South America and I used to fly there from Europe in the holidays. A flight attendant would take care of me and I never had an unpleasant experience. I am used to traveling by air and only once have I ever felt scared. After taking off, we were flying low over the city and slowly gaining height(逐步升高), when the plane suddenly turned round and flew back to the airport. While we were waiting to land, a flight attendant told us to keep calm and to get off the plane quietly as soon as it had landed. Everybody was worried and we wanted to know what had happened. Later we learned that there was a very important person on the plane. The police were told that a bomb(炸弹).had been put on the plane. After we landed, the plane was searched thoroughly(彻底地). Luckily, nothing was found and five hours later we were able to take off again.( )41.The writer used to fly much when he was a boy.( )42.The writer‟s parents used to live in South Africa.( )43.While they were waiting to land, a flight attendant told them not to be calm.( )44.Nothing was found and nine hours later they could take off again.( )45.The police wanted to find important person on the plane.第二节:阅读下面B、C、D三篇短文,从各小题所给的四个选项中选出能回答所提问题或完成所给句子的一个最佳答案.(共10小题,计15分)BHundreds of years ago there lived a king in a small country. He liked swimming. When summ er came, he always went to another palace by a forest with his guards and returned to the capital i n autumn.One afternoon the king went swimming in a river in the forest but he didn‟t tell others abou t it.He was very happy when he swam in the water. After that he heard a great noise and saw a bi g bear coming at him. He tried his best to run away. He ran and ran and at last he lost his way. H e was hungry and tired when he found an old house. There was an old farmer in it. “It‟s your kin g,” he said to the old man. “I‟m hungry now. Bring me something to eat quickly!”The old man had nothing valuable. He only had four eggs. The king ate them and felt better. “How much must I pay you for that?”“Eighteen pounds. ”“How expensive they are! Are eggs rare (稀有的)here?”“No,” answered the old farmer. “We have only one king in our country!”46. When the king saw the bear,he __________ .A. asked the old farmer to help himB. cried for helpC. ran away quicklyD. ran outside the forest47. The King felt better because __________ .A. he could sleep in the farmer‟s houseB. the bear couldn‟t find himC. he ate four eggsD. the farmer knew he was a king48. Which is the best title of the story?A. The King and the Old FarmerB. The King in the ForestC. The King and the BearD. The Kind hearted KingCDuring my visit to a school in Canada, what I heard most often were words like these: “Please do in pairs”,“Four students a group.”In Canada, students act in groups. Their team spirit really surprised me.This was a writing lesson. The teacher asked the students to work in groups. It meant they wrote one article(文章) together! A group had five students. The first student wrote the beginning of the story. He had only one minute. He had to pass his unfinished article to the next student when the teacher said,“Stop!”The second student w ent on with the story, and then the third, the fourth and finally the fifth one. The last student tried his best to finish the story with a good ending. Each of them had the same time limit(限制).The students soon finished their articles. They were all excited because the lesson actually went like a competition. Learning how to write through competing should be fun to students. I think our Chinese kids would not be afraid of writing any more, if they had a lesson like this.We all know that cooperation is important, but how to develop this ability? I do think we can learn something from schools in Canada. Maybe it‟s a good idea to begin with group activities!49. We can infer(推断) from the passage __________ in Canada.A. students like writing storiesB. students are good at teamworkC. kids don‟t have team spiritD. teachers often work in groups50. Which is the correct order of the following events?①Then another student went to with the story.②The first student wrote the beginning of the story.③The last student tried his best to finish the story with a good ending.④The teacher asked the students to write one article together.A.①③④②B.③④②①C.④②①③D.②①③④51. The underlined word“cooperation”in the passage means __________ .A. writing lessonsB. teamworkC. helping othersD. homework52. The Writer suggests that the students in China should __________ .A. go to visit the school in CanadaB. not be afraid of writingC. have a writing lesson every dayD. learn team spirit from schools in CanadaDMr and Mrs Kelly had been married for fifteen years. Every day, when Mr Kelly came home from work, he would come in the front door and call out, “Hi, honey, I‟m home!” and Mrs Kelly call back, “Hi, sweetheart, I‟m in the kitchen!”or “Hi, sweetheart, I‟m in the living room.”But lately, when Mr Kelly came home and called out, Mrs Kelly didn‟t say anything, and Mr Kelly was getting worried. There were other times when she didn‟t answer him when he spoke toher or asked her a question. He wondered if his wife was becoming deaf.He asked the doctor for advice. “What should I do?” he asked the doctor. “Should I buy her some hearing aids?”The doctor told him that he should do some tests at home first, to be certain there really was a problem.“Find out just how bad her hearing is, and then ask her to come in and see me,” he said.Mr Kelly went home. He came in the front door and called out very loudly, “Hi, honey, I‟m home!” but there was no answer.“Oh dear,” he thought. “Her hearing is getting worse every day.”He went to the kitchen and saw Mrs Kelly standing near the kitchen sink preparing dinner.“Ah,” he said to himself, “this is my chance to test her hearing.” Standing at the door, he asked “What‟s for dinner tonight, dear?” There was no answer, so he moved closer, and asked again. “What‟s for dinner tonight, dear?” But again there was no answer, and now Mr Kelly was very worried. He came closer and stood right behind her. He asked her a third time.Mrs Kelly turned around a nd shouted, “For the third time, it‟s chicken!”53. Why is this story funny?A. The man can‟t hear clearly.B. The woman can‟t hear clearly.C. The doctor has bad hearing.D. The man, the woman and the doctor are all deaf.54. How did he test his wife‟s hearing?A. He made a loud noise.B. He said something funny.C. He whispered.D. He spoke when he was behind her.55. What does “call out” mean in the story?A. use the phoneB. tell to leaveC. say loudlyD. ask to come第二卷非选择题(共55分)Ⅳ、完成句子:根据所给汉语意思,用单词或短语完成下列英文句子.(共5小题,计10分)56.与打篮球相比,我更喜欢听音乐.I __________ listening to music to __________ basketball.57.我的手表坏了.我得找人去修理了.My watch is __________ and I have to get it __________ .58.我喜欢我能跟着唱的音乐.I like music that I can __________ .59.这些蓝大衣是羊毛制作的,手感很柔软.These blue coats __________ wool and they feel very __________ .60.如果你坚持你的梦想,终有一天它会成真的.If you __________ your dream, it will come true someday.Ⅶ、短文填空(共10小题,计10分)用方框中所给单词的适当形式填空,使短文完整正确.(每个单词限用一次,每空只填一个单词)(共10小题,计10分)We celebrated the Dragon Boat Festival last week. And I felt (61)__________ this year because I did something special. I made zongzi with my classmates!On that day, our class was (62)__________ us into five groups. I had eight helpers in my group, but at first, I still doubted (63)__________ I could finish the task.Before we started, we had watched the teaching video. Our teacher told us to be careful while working. He told us to (64)__________ spreading rice about. When he said “Try it (65)__________ now!”, I was so nervous. I looked at those reed (芦苇) (66)__________ and rice and had no idea about all this stuff(材料). But I didn‟t want to lose. I tried my best to think (67)__________ my grandmother did it when I was a child. She always made the perfect zongzi for us. Right! “I just need to do what she did,” I told myself. Of course, things were not so easy as I thought. I (68)__________ a few times. Jimmy laughed at me when he saw my ugly(丑陋的) zongzi.Hard work paid off. I (69)__________ to make my own zongzi! It was small, but it (70)__________ nice. It encouraged everyone in my team! Finally, we made seven zongzi and won the game.Yours,Li HongⅧ、任务型阅读:阅读下面短文,根据短文内容,完成下列各题.(共5小题,计10分) Confidence is very important in daily life. It can help you to develop a healthy attitude (态度).A study shows that the people who are more confident are much happier. They can have more chance to make themselves successful. But how to be more confident? Here are some suggestions:*Speak in a loud voice When you are not confident, you can‟t do well what you want to do. You speak in a voice so low that other people can hardly hear you. Try to speak in a loud voice so that people can hear you clearly. The high voice can help you become more confident.*Play sports Physical exercise makes you tired but completely relaxed. A strong body helps you be full of confidence. Encourage yourself. Write down a list of things you did during the day to see how many things you have done well. Did you finish your homework? Did you tell a joke that made everybody laugh? Give yourself praisefor the good things you‟ve done.*Get rid of (消除)fear Fear comes along with failure (失败). But if you know that failure is part of your life. It‟s easy to get over it. Don‟t hide your head just because you said something stupid last time. Try to start again and believe you can do better.*Pick up a hobby If you like singing, sing as much as you can. In some ways, a hobby can make you outstanding. And it will make you happy and confident.71. What does the first paragraph tell us?The first paragraph tells us why __________ is important.72. How many suggestions about how to be more confident are mentioned in this passage?______________________________________________________________________________ 73. What does “it” refer to in the 4th paragraph?It refers to _________________74. Why do you need to pick up a hobby?Because a hobby can make us __________, happy and _____________75. Is it helpful to be more confident by encouraging or praising yourself?____________________________________________________________________________Ⅸ、补全对话.(每空1分,共10分)(A).从上面的方框中选择适当的句子补全对话.A: Hello, this is Laura. May I speak to Cindy?B: Hi, Cindy speaking.A: (76)___________________B: I‟m watching a movie on the Internet.A: (77)____________________B: A popular movie called Zootopia .(《疯狂动物城》).A: (78)____________________B: Yes,it‟s about animals‟dreams. I am deeply moved by it.A: Sounds good. I‟ll enjoy it when I‟m free.B: I‟m sure you‟ll like it.(79)________________A: Oh, I found an interesting place to go for a picnic. Do you want to join us tomorrow?B: Umm, let me have a look first. (80)______________A: Sure. Please do remember to give me a reply.B: OK. Thanks for calling.,使对话恢复完整.A: Hi, Tina. You look terrible, 81. _____________________________?B: Oh, I‟m not feeling well. I have a headache.A: 82. ________________. When did it start?B: Several hours ago.A: 83. ________________?B: Yes, I did. You know I do sports every morning.A: But look at the serious Haze(雾霾). It‟s bad for your health to stay outside.B: Oh, I didn‟t know that. 84. __________________________ ?A: You should stay at home and keep your windows closed. Try not to go out.B: 85. __________________________________ .A: You‟re welcome. I hope you can get better soon.Ⅹ、书面表达(共1题,计15分)国有国法,校有校规.在你的学校中一定有很多规章制度来规范中学生的行为,使学生们都能健康成长.请你以“My School Rules”为题,写一篇小短文向大家介绍某些校规、校纪,并用自己的观点来评价.(70词左右)要求:1.参考提示内容,可适当发挥.2.语句通顺,意思连贯,书写工整.3.文中不得出现真实姓名和校名.提示:get to school early, take mobile phones, do sports every morning, have long hair, agree/disagree, allow, because_______________________________________________________________________________ ______________________________________________________________________________________________________________________________________________________________ _______________________________________________________________________________。
2016年陕西省西安市雁塔区益新中学数学中考一模试卷及参考答案PDF

2016年陕西省西安市雁塔区益新中学中考数学一模试卷一、选择题1.(3分)在△ABC中,∠C=90°,如果sinA=,那么tanB的值等于()A.B.C.D.2.(3分)将抛物线y=x2先向右平移1个单位长度,再向下平移2个单位长度可得抛物线()A.y=(x﹣1)2﹣2 B.y=(x+1)2﹣2 C.y=(x﹣1)2+2 D.y=(x+1)2+2 3.(3分)如图,C是⊙O上一点,O是圆心,若∠C=35°,则∠AOB的度数为()A.35°B.70°C.105° D.150°4.(3分)如图,在网格中,小正方形的边长均为1,点A,B,C都在格点上,则∠ABC的正切值是()A.2 B.C.D.5.(3分)设点Q到图形W上每一个点的距离的最小值称为点Q到图形W的距离.在直角坐标系中,如果⊙P是以(3,4)为圆心,1为半径的圆,那么点O (0,0)到⊙P的距离为?()A.3 B.4 C.5 D.66.(3分)已知二次函数y=ax2+bx+c(a≠0)的图象如图所示,有下列结论:①b2﹣4ac>0;②abc>0;③8a+c>0;④9a+3b+c<0其中,正确结论的个数是()A.1 B.2 C.3 D.47.(3分)如图,A,B,E为⊙O上的点,⊙O的半径OC⊥AB于点D,若∠CEB=30°,OD=1,则AB的长为()A.B.4 C.2 D.68.(3分)如图,四个二次函数的图象中,分别对应的是:①y=ax2;②y=bx2;③y=cx2;④y=dx2,则a,b,c,d的大小关系是()A.a>b>c>d B.a>b>d>c C.b>a>c>d D.b>a>d>c9.(3分)如图是拦水坝的横断面,斜坡AB的水平宽度为12米,斜面坡度为1:2,则斜坡AB的长为()A.4米B.6米C.12米D.24米10.(3分)如图,⊙O的半径是2,直线l与⊙O相交于A、B两点,M、N是⊙O上的两个动点,且在直线l的异侧,若∠AMB=45°,则四边形MANB面积的最大值是()A.2 B.4 C.4 D.8二、填空题11.(3分)如图,AB是⊙O的直径,点C在AB的延长线上,CD与⊙O相切,切点为D.如果∠A=35°,那么∠C等于.12.(3分)如图,一块含有30°角的直角三角形ABC,在水平桌面上绕点C按顺时针方向旋转到A′B′C′的位置.若BC的长为15cm,那么顶点A从开始到结束所经过的路径长为.13.(3分)如图,PA、PB、DE分别切⊙O于点A、B、C,DE交PA、PB于点D、E,若∠P=40°,则∠DOE=.14.(3分)如图,正方形ABCD内接于⊙O,AD=2,弦AE平分BC交BC于P,连接CE,则CE的长为.三、解答题15.计算:2sin30°+4cos30°•tan60°﹣cos245°.16.已知抛物线y=x2+bx+c经过点(1,﹣4)和(﹣1,2),求这个抛物线的顶点坐标.17.如图,一段圆弧AB上有一个点D,直线AC与圆弧相切于点A,请借助于切点A及B、D两点,利用尺规作图找出这段圆弧所在圆的圆心(不写作法,保留作图痕迹).18.如图,在直径为50 cm的圆中,有两条弦AB和CD,AB∥CD,且AB为40 cm,弦CD为48 cm,求AB与CD之间距离.19.如图,在△ABC中,∠A=90°,O是BC边上一点,以O为圆心的半圆分别与AB、AC边相切于D、E两点,连接OD.已知BD=2,AD=3.求:(1)tanC;(2)图中两部分阴影面积的和.20.我国中东部地区雾霾天气趋于严重,环境治理已刻不容缓.我市某电器商场根据民众健康需要,代理销售某种家用空气净化器,其进价是200元/台.经过市场销售后发现:在一个月内,当售价是400元/台时,可售出200台,且售价每降低10元,就可多售出50台.若供货商规定这种空气净化器售价不能低于300元/台,代理销售商每月要完成不低于450台的销售任务.(1)试确定月销售量y(台)与售价x(元/台)之间的函数关系式;(2)求售价x的范围;(3)当售价x(元/台)定为多少时,商场每月销售这种空气净化器所获得的利润w(元)最大?最大利润是多少?21.今年“五一”假期.某数学活动小组组织一次登山活动.他们从山脚下A点出发沿斜坡AB到达B点.再从B点沿斜坡BC到达山巅C点,路线如图所示.斜坡AB的长为1040米,斜坡BC的长为400米,在C点测得B点的俯角为30°,点C到水平线AM的距离为600米.(1)求B点到水平线AM的距离.(2)求斜坡AB的坡度.22.已知抛物线y=x2﹣2x﹣3与x轴交于点A,B(点A在点B左侧),其顶点为P,直线y=kx+b过抛物线与x轴的一个交点A,且与抛物线相交的另外一个交点为C,若S=10,请你回答下列问题:△ABC(1)求直线的解析式;(2)求四边形APBC的面积.23.如图,⊙O的直径AB垂直于弦CD,垂足为点E,过点C作⊙O 的切线,交AB的延长线于点P,联结PD.(1)判断直线PD与⊙O的位置关系,并加以证明;(2)联结CO并延长交⊙O于点F,联结FP交CD于点G,如果CF=10,cos∠APC=,求EG的长.24.如图,已知:AB是⊙O的直径,点C是⊙O上的一点,切线CD交AB的延长线于D.(1)求证:△CBD∽△ACD.(2)若CD=4,BD=2,求直径AB的长.(3)在(2)的前提下求tan∠CAB的值.25.在平面直角坐标系xOy中,抛物线y=mx2﹣2mx﹣3(m≠0)与x轴交于A (3,0),B两点.(1)求抛物线的表达式及点B的坐标;(2)当﹣2<x<3时的函数图象记为G,求此时函数y的取值范围;(3)在(2)的条件下,将图象G在x轴上方的部分沿x轴翻折,图象G的其余部分保持不变,得到一个新图象M.若经过点C(4,2)的直线y=kx+b(k≠0)与图象M在第三象限内有两个公共点,结合图象求b的取值范围.2016年陕西省西安市雁塔区益新中学中考数学一模试卷参考答案与试题解析一、选择题1.(3分)在△ABC中,∠C=90°,如果sinA=,那么tanB的值等于()A.B.C.D.【解答】解:∵在Rt△ABC中,∠C=90°,sinA=,tanB=,a2+b2=c2,又∵sinA=知,∴设a=3x,则c=5x,b=4x.∴tanB=.故选D.2.(3分)将抛物线y=x2先向右平移1个单位长度,再向下平移2个单位长度可得抛物线()A.y=(x﹣1)2﹣2 B.y=(x+1)2﹣2 C.y=(x﹣1)2+2 D.y=(x+1)2+2【解答】解:抛物线y=x2先向右平移1个单位长度,再向下平移2个单位长度可得抛物线y=(x﹣1)2﹣2,故选:A.3.(3分)如图,C是⊙O上一点,O是圆心,若∠C=35°,则∠AOB的度数为()A.35°B.70°C.105° D.150°【解答】解:根据圆周角定理,可得:∠O=2∠C=70°.故选B.4.(3分)如图,在网格中,小正方形的边长均为1,点A,B,C都在格点上,则∠ABC的正切值是()A.2 B.C.D.【解答】解:如图:,由勾股定理,得AC=,AB=2,BC=,∴△ABC为直角三角形,∴tan∠B==,故选:D.5.(3分)设点Q到图形W上每一个点的距离的最小值称为点Q到图形W的距离.在直角坐标系中,如果⊙P是以(3,4)为圆心,1为半径的圆,那么点O (0,0)到⊙P的距离为?()A.3 B.4 C.5 D.6【解答】解:如图,连接OP交⊙P于E,作PF⊥x轴于F.∵P(3,4),∴OF=3,PF=4,在Rt△POF中,OP===5,∵PE=1,∴OE=4,由题意点O(0,0)到⊙P的距离为4.故选B.6.(3分)已知二次函数y=ax2+bx+c(a≠0)的图象如图所示,有下列结论:①b2﹣4ac>0;②abc>0;③8a+c>0;④9a+3b+c<0其中,正确结论的个数是()A.1 B.2 C.3 D.4【解答】解:①由图知:抛物线与x轴有两个不同的交点,则△=b2﹣4ac>0,故①正确;②抛物线开口向上,得:a>0;抛物线的对称轴为x=﹣=1,b=﹣2a,故b<0;抛物线交y轴于负半轴,得:c<0;所以abc>0;故②正确;③根据②可将抛物线的解析式化为:y=ax2﹣2ax+c(a≠0);由函数的图象知:当x=﹣2时,y>0;即4a﹣(﹣4a)+c=8a+c>0,故③正确;④根据抛物线的对称轴方程可知:(﹣1,0)关于对称轴的对称点是(3,0);当x=﹣1时,y<0,所以当x=3时,也有y<0,即9a+3b+c<0;故④正确;所以这四个结论都正确.故选:D.7.(3分)如图,A,B,E为⊙O上的点,⊙O的半径OC⊥AB于点D,若∠CEB=30°,OD=1,则AB的长为()A.B.4 C.2 D.6【解答】解:连接OB,∵AB是⊙O的一条弦,OC⊥AB,∴AD=BD,即AB=2BD,∵∠CEB=30°,∴∠COB=60°,∵OD=1,∴BD=1×tan60°=,∴AB=2,故选C.8.(3分)如图,四个二次函数的图象中,分别对应的是:①y=ax2;②y=bx2;③y=cx2;④y=dx2,则a,b,c,d的大小关系是()A.a>b>c>d B.a>b>d>c C.b>a>c>d D.b>a>d>c【解答】解:由二次函数y=ax2的性质知,(1)抛物线y=ax2的开口大小由|a|决定.|a|越大,抛物线的开口越窄;|a|越小,抛物线的开口越宽.(2)抛物线y=ax2的开口方向由a决定.当a>0时,开口向上,抛物线(除顶点外)都在x轴上方;当a<0时,开口向下,抛物线(除顶点外)都在x轴下方.根据以上结论知:a>b>0,0>c>d.故选A.9.(3分)如图是拦水坝的横断面,斜坡AB的水平宽度为12米,斜面坡度为1:2,则斜坡AB的长为()A.4米B.6米C.12米D.24米【解答】解:在Rt△ABC中,∵i==,AC=12米,∴BC=6米,根据勾股定理得:AB==6米,故选:B.10.(3分)如图,⊙O的半径是2,直线l与⊙O相交于A、B两点,M、N是⊙O上的两个动点,且在直线l的异侧,若∠AMB=45°,则四边形MANB面积的最大值是()A.2 B.4 C.4 D.8【解答】解:过点O作OC⊥AB于C,交⊙O于D、E两点,连结OA、OB、DA、DB、EA、EB,如图,∵∠AMB=45°,∴∠AOB=2∠AMB=90°,∴△OAB为等腰直角三角形,∴AB=OA=2,=S△MAB+S△NAB,∵S四边形MANB∴当M点到AB的距离最大,△MAB的面积最大;当N点到AB的距离最大时,△NAB的面积最大,即M点运动到D点,N点运动到E点,=S△DAB+S△EAB=AB•CD+AB•CE=AB 此时四边形MANB面积的最大值=S四边形DAEB(CD+CE)=AB•DE=×2×4=4.故选C.二、填空题11.(3分)如图,AB是⊙O的直径,点C在AB的延长线上,CD与⊙O相切,切点为D.如果∠A=35°,那么∠C等于20°.【解答】解:如图,连接OD,∵CD是⊙O的切线,∴OD⊥CD,即∠ODC=90°,∵AB为直径,∴∠COD=2∠A=70°,∴∠C=90°﹣70°=20°,故答案为:20°.12.(3分)如图,一块含有30°角的直角三角形ABC,在水平桌面上绕点C按顺时针方向旋转到A′B′C′的位置.若BC的长为15cm,那么顶点A从开始到结束所经过的路径长为20πcm.【解答】解:=20πcm.故答案为20πcm.13.(3分)如图,PA、PB、DE分别切⊙O于点A、B、C,DE交PA、PB于点D、E,若∠P=40°,则∠DOE=70°.【解答】解:如图,分别连接OA、OB、OC,∵PA、PB、DE分别切⊙O于点A、B、C,∴∠OAP=∠OBP=90°,∴∠AOB=360°﹣90°﹣90°﹣∠P=140°,∵DA、DC是⊙O的切线,∴OD平分∠AOC,∴∠DOC=∠AOC,同理可得∠EOC=∠BOC,∴∠DOE=∠DOC+∠EOC=(∠AOC+∠BOC)=∠AOB=70°,故答案为:70°.14.(3分)如图,正方形ABCD内接于⊙O,AD=2,弦AE平分BC交BC于P,连接CE,则CE的长为.【解答】解:连接AC,BE,如图所示:∵四边形ABCD是正方形,∴BC=AB=2,∵AE平分BC,∴BM=CM=1,∵四边形ABCD为圆内正方形,∴AC必过圆心O,且∠AEC=∠ABC=90°,∵∠CME=∠AMB,∴△AMB∽△CME,∴.∵AM===,∴,∴CE=.故答案为.三、解答题15.计算:2sin30°+4cos30°•tan60°﹣cos245°.【解答】解:原式=2×+4ו﹣=1+6﹣=.16.已知抛物线y=x2+bx+c经过点(1,﹣4)和(﹣1,2),求这个抛物线的顶点坐标.【解答】解:(1)把点(1,﹣4)和(﹣1,2)代入y=x2+bx+c,得,解得,所以抛物线的解析式为y=x2﹣3x﹣2.y=x2﹣3x﹣2=(x﹣)2﹣,所以抛物线的顶点坐标为(,﹣).17.如图,一段圆弧AB上有一个点D,直线AC与圆弧相切于点A,请借助于切点A及B、D两点,利用尺规作图找出这段圆弧所在圆的圆心(不写作法,保留作图痕迹).【解答】解:如图,点O为所作.18.如图,在直径为50 cm的圆中,有两条弦AB和CD,AB∥CD,且AB为40 cm,弦CD为48 cm,求AB与CD之间距离.【解答】解:如图1所示,过O作OM⊥AB,∵AB∥CD,∴ON⊥CD.在Rt△BMO中,BO=25cm.由垂径定理得BM=AB=×40=20cm,∴OM===15cm.同理可求ON===7cm,∴MN=OM﹣ON=15﹣7=8cm.当两弦位于圆心的两旁时,如图2所示:过O作OM⊥AB,∵AB∥CD,∴ON⊥CD.在Rt△BMO中,BO=25cm.由垂径定理得BM=AB=×40=20cm,∴OM===15cm.同理可求ON===7cm,则MN=OM+ON=15+7=22(cm).综上所示,AB与CD之间的距离为8cm或22cm.19.如图,在△ABC中,∠A=90°,O是BC边上一点,以O为圆心的半圆分别与AB、AC边相切于D、E两点,连接OD.已知BD=2,AD=3.求:(1)tanC;(2)图中两部分阴影面积的和.【解答】解:(1)连接OE,∵AB、AC分别切⊙O于D、E两点,∴AD⊥OD,AE⊥OE,∴∠ADO=∠AEO=90°,又∵∠A=90°,∴四边形ADOE是矩形,∵OD=OE,∴四边形ADOE是正方形,∴OD∥AC,OD=AD=3,∴∠BOD=∠C,∴在Rt△BOD中,,∴.答:tanC=.(2)如图,设⊙O 与BC 交于M 、N 两点,由(1)得:四边形ADOE 是正方形,∴∠DOE=90°,∴∠COE +∠BOD=90°,∵在Rt △EOC 中,=,OE=3, ∴,∴S 扇形DOM +S 扇形EON =S 扇形DOE =,∴S 阴影=S △BOD +S △COE ﹣(S 扇形DOM +S 扇形EON )=, 答:图中两部分阴影面积的和为.20.我国中东部地区雾霾天气趋于严重,环境治理已刻不容缓.我市某电器商场根据民众健康需要,代理销售某种家用空气净化器,其进价是200元/台.经过市场销售后发现:在一个月内,当售价是400元/台时,可售出200台,且售价每降低10元,就可多售出50台.若供货商规定这种空气净化器售价不能低于300元/台,代理销售商每月要完成不低于450台的销售任务.(1)试确定月销售量y (台)与售价x (元/台)之间的函数关系式;(2)求售价x 的范围;(3)当售价x (元/台)定为多少时,商场每月销售这种空气净化器所获得的利润w (元)最大?最大利润是多少?【解答】解:(1)根据题中条件销售价每降低10元,月销售量就可多售出50台,则月销售量y (台)与售价x (元/台)之间的函数关系式:y=200+50×,化简得:y=﹣5x +2200;(2)根据供货商规定这种空气净化器售价不能低于300元/台,代理销售商每月要完成不低于450台,则,解得:300≤x≤350.所以y与x之间的函数关系式为:y=﹣5x+2200(300≤x≤350);(3)W=(x﹣200)(﹣5x+2200),整理得:W=﹣5(x﹣320)2+72000.∵x=320在300≤x≤350内,∴当x=320时,最大值为72000,即售价定为320元/台时,商场每月销售这种空气净化器所获得的利润w最大,最大利润是72000元.21.今年“五一”假期.某数学活动小组组织一次登山活动.他们从山脚下A点出发沿斜坡AB到达B点.再从B点沿斜坡BC到达山巅C点,路线如图所示.斜坡AB的长为1040米,斜坡BC的长为400米,在C点测得B点的俯角为30°,点C到水平线AM的距离为600米.(1)求B点到水平线AM的距离.(2)求斜坡AB的坡度.【解答】解:(1)如图,过C作CF⊥AM,F为垂足,过B点作BE⊥AM,BD⊥CF,E、D为垂足,在C点测得B点的俯角为30°,∴∠CBD=30°,又BC=400米,∴CD=400×sin30°=400×=200(米),∴BE=DF=CF﹣CD=600﹣200=400(米),即B点到水平线AM的距离为400米;(2)∵BE=400米,AB=1040米,∠AEB=90°,∴AE===960(米),∴斜坡AB的坡度i AB====1:2.4,故斜坡AB的坡度为1:2.4.22.已知抛物线y=x2﹣2x﹣3与x轴交于点A,B(点A在点B左侧),其顶点为P,直线y=kx+b过抛物线与x轴的一个交点A,且与抛物线相交的另外一个交点为C,若S△ABC=10,请你回答下列问题:(1)求直线的解析式;(2)求四边形APBC的面积.【解答】解:(1)令y=0,则x2﹣2x﹣3=0,解得:x1=﹣1,x2=3,∴A(﹣1,0),B(3,0),设C(m,m2﹣2m﹣3),∴S△ABC=×4×|m2﹣2m﹣3|=10,∴m=4或m=﹣2,∴C(4,5)或(﹣2,5),∴或,∴或,∴直线的解析式为:y=x+1或y=﹣5x﹣5;(2)如图,∵y=x2﹣2x﹣3=(x﹣1)2﹣4,∴P(1,﹣4),∵A(﹣1,0),B(3,0),∴四边形APBC的面积=S△ABC +S△ABP=×4×5+×4×4=18.23.如图,⊙O的直径AB垂直于弦CD,垂足为点E,过点C作⊙O 的切线,交AB的延长线于点P,联结PD.(1)判断直线PD与⊙O的位置关系,并加以证明;(2)联结CO并延长交⊙O于点F,联结FP交CD于点G,如果CF=10,cos∠APC=,求EG的长.【解答】(1)PD与⊙O相切于点D;证明:连接OD∵在⊙O中,OD=OC,AB⊥CD于点E,∴∠COP=∠DOP.在△OCP和△ODP中∴△OCP≌△ODP(SAS).∴∠OCP=∠ODP.又∵PC切⊙O于点C,OC为⊙O半径,∴OC⊥PC,∴∠OCP=90°.∴∠ODP=90°.∴OD⊥PD于点D.∴PD与⊙O相切于点D.(2)作FM⊥AB于点M.∵∠OCP=90°,CE⊥OP于点E,∴∠3+∠4=90°,∠APC+∠4=90°.∴∠3=∠APC.∵,∴Rt△OCE中,.∵CF=10,∴.∴CE=4,OE=3.又∵FM⊥AB,AB⊥CD,∴∠FMO=∠CEO=90°.在△OFM和△OCE中∴△OFM≌△OCE(AAS).∴FM=CE=4,OM=OE=3.∵在Rt△OCE中,,设PC=4k,OP=5k,∴OC=3k.∴3k=5,.∴.∴,.又∵∠FMO=∠GEP=90°,∴FM∥GE.∴△PGE∽△PFM.∴,即.∴.24.如图,已知:AB是⊙O的直径,点C是⊙O上的一点,切线CD交AB的延长线于D.(1)求证:△CBD∽△ACD.(2)若CD=4,BD=2,求直径AB的长.(3)在(2)的前提下求tan∠CAB的值.【解答】(1)证明:∵AB为直径,∴∠ACB=90°,即∠ACO+∠BCO=90°,∵CD为切线,∴OC⊥CD,∴∠BCO+∠BCD=90°,∴∠BCD=∠ACO,∵OA=OC,∴∠ACO=∠A,∴∠A=∠BCD,而∠BDC=∠CDA,∴△CBD∽△ACD;(2)解:∵△CBD∽△ACD,∴DC:DA=DB:DC,即4:(2+AB)=2:4,∴AB=6;(3)解:∵△CBD∽△ACD,∴===,在Rt△ABC中,tan∠CAB==.25.在平面直角坐标系xOy中,抛物线y=mx2﹣2mx﹣3(m≠0)与x轴交于A (3,0),B两点.(1)求抛物线的表达式及点B的坐标;(2)当﹣2<x<3时的函数图象记为G,求此时函数y的取值范围;(3)在(2)的条件下,将图象G在x轴上方的部分沿x轴翻折,图象G的其余部分保持不变,得到一个新图象M.若经过点C(4,2)的直线y=kx+b(k≠0)与图象M在第三象限内有两个公共点,结合图象求b的取值范围.【解答】解:(1)将A(3,0)代入,得m=1.∴抛物线的表达式为y=x2﹣2x﹣3.B点的坐标(﹣1,0).(2)y=x2﹣2x﹣3=(x﹣1)2﹣4.∵当﹣2<x<1时,y随x增大而减小;当1≤x<3时,y随x增大而增大,=﹣4.∴当x=1,y最小当x=﹣2,y=5.∴y的取值范围是﹣4≤y<5.(3)当直线y=kx+b经过B(﹣1,0)和点(4,2)时,解析式为y=x+.当直线y=kx+b经过(﹣2,﹣5)和点(4,2)时,解析式为y=x﹣.结合图象可得,b的取值范围是﹣<b<.。
2016年陕西省西安市雁塔区益新中学中考数学三模试卷和解析

21.高考英语听力测试期间,需要杜绝考点周围的噪音.如图,点 A 是某市一高 考考点,在位于 A 考点南偏西 15°方向距离 125 米的 C 处有一消防队.在听力考 试期间,消防队突然接到报警电话,告知在位于 C 点北偏东 75°方向的 F 点处突 发火灾,消防队必须立即赶往救火.已知消防车的警报声传播半径为 100 米,若 消防车的警报声对听力测试造成影响,则消防车必须改进行驶,试问:消防车是 否需要改道行驶?请说明理由. ( 取 1.732)
15. (3 分)如图,⊙O 的半径为 1cm,弦 AB、CD 的长度分别为 则弦 AC、BD 所夹的锐角 α= 度.
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请从以下两个小题中任选一个作答,若多选,则按所选的第一题计分. 12. (3 分)在矩形 ABCD 中,AB=3,BC=4,BD 的垂直平分线交 AD 于 E,则 AE 的长为 . ,则 AB 的长为 . (用
(1)求被调查的学生人数; (2)补全两个统计图 (3)若全校有 1500 人,估计该校学生上学坐地铁的人数,并根据调查结果,请 你对西安开通地铁对学生上学的影响谈谈你的感想或建议. 20.如图,在正方形 ABCD 中,等边三角形 AEF 的顶点 E、F 分别在 BC 和 CD 上. (1)求证:CE=CF; (2)若等边三角形 AEF 的边长为 2,求正方形 ABCD 的周长.
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二.填空题 11. (3 分例函数 y= (x>0)的图象经过平行四边形 ABCO 的顶点 A 和对角线的交点 E, 点 A 的横坐标为 3, 对角线 AC 所在的直线交 y 轴于 (0, 6) 点,则函数 y= 的表达式为 .
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C.10 D.11
7. (3 分)若正方形的边长为 6,则其外接圆半径与内切圆半径的大小分别为 ( ) B. ,3 C.6,3 D. ,
陕西省西安市中考数学三模试卷(含解析)
2016年陕西省西安市益新中学中考数学三模试卷一.选择题1.计算:﹣1﹣2=()A.1 B.﹣1 C.﹣2 D.﹣32.如图,由两个相同的正方体和一个圆锥体组成一个立体图形,其俯视图是()A.B.C.D.3.下列运算正确的是()A.(﹣2a)3=﹣6a3B.﹣3a2•4a3=﹣12a5C.﹣3a(2﹣a)=6a﹣3a2D.2a3﹣a2=2a4.如图,在Rt△ACB中,∠ACB=90°,∠A=25°,D是AB上一点.将Rt△ABC沿CD折叠,使B点落在AC边上的B′处,则∠ADB′等于()A.40° B.35° C.30° D.25°5.若正比例函数的图象经过点(﹣1,2),(﹣m,4﹣2m),则m的值为()A.﹣1 B.﹣2 C.2 D.16.如图,▱ABCD的对角线AC与BD相交于点O,AB⊥AC,若AB=4,AC=6,则BD的长是()A.8 B.9 C.10 D.117.若正方形的边长为6,则其外接圆半径与内切圆半径的大小分别为()A.6,B.,3 C.6,3 D.,8.在平面直角坐标系中,把直线y=2x向左平移1个单位长度,平移后的直线解析式是()A.y=2x+1 B.y=2x﹣1 C.y=2x+2 D.y=2x﹣29.如图,在菱形ABCD中,∠A=60°,E、F分别是AB,AD的中点,DE、BF相交于点G,连接BD,CG.有下列结论:①∠BGD=120°;②BG+DG=CG;③△BDF≌△CGB;④S△ABD=AB2其中正确的结论有()A.1个B.2个C.3个D.4个10.已知抛物线y=ax2+bx﹣2与x轴没有交点,过A(﹣、y1)、B(﹣3,y2)、C(1,y2)、D(,y3)四点,则y1、y2、y3的大小关系是()A.y1>y2>y3B.y2>y1>y3C.y1>y3>y2D.y3>y2>y1二.填空题11.分解因式:x3y2﹣4x= .14.如图,反比例函数y=(x>0)的图象经过平行四边形ABCO的顶点A和对角线的交点E,点A的横坐标为3,对角线AC所在的直线交y轴于(0,6)点,则函数y=的表达式为.15.如图,⊙O的半径为1cm,弦AB、CD的长度分别为cm,1cm,则弦AC、BD所夹的锐角α= 度.请从以下两个小题中任选一个作答,若多选,则按所选的第一题计分.12.在矩形ABCD中,AB=3,BC=4,BD的垂直平分线交AD于E,则AE的长为.13.在 Rt△ABC中,∠ACB=90°,∠A=41°,BC=3,则AB的长为.(用科学计算器计算,结果精确到0.01)三、解答题16.求不等式组的整数解.17.先化简,再求值:,其中x=+1.18.如图,已知线段a,c.求作Rt△ABC,使∠C=90°,AB=c,BC=a(尺规作图,保留作图痕迹).19.西安市地铁改变了人们的出行情况,也改变了学生到校的方式.小明同学就本校学生上学方式进行了一次统计调查,如图是他采集数据后绘制的两幅不完整的统计图.请你根据图中提供的信息回答以下问题:(A:步行,B:乘公交,C:坐地铁,D:骑自行车).(1)求被调查的学生人数;(2)补全两个统计图(3)若全校有1500人,估计该校学生上学坐地铁的人数,并根据调查结果,请你对西安开通地铁对学生上学的影响谈谈你的感想或建议.20.如图,在正方形ABCD中,等边三角形AEF的顶点E、F分别在BC和CD上.(1)求证:CE=CF;(2)若等边三角形AEF的边长为2,求正方形ABCD的周长.21.高考英语听力测试期间,需要杜绝考点周围的噪音.如图,点A是某市一高考考点,在位于A考点南偏西15°方向距离125米的C处有一消防队.在听力考试期间,消防队突然接到报警电话,告知在位于C点北偏东75°方向的F点处突发火灾,消防队必须立即赶往救火.已知消防车的警报声传播半径为100米,若消防车的警报声对听力测试造成影响,则消防车必须改进行驶,试问:消防车是否需要改道行驶?请说明理由.(取1.732)22.某蔬菜生产基地经市场调查,对种植的A、B、C三种蔬菜的成本与售价情况统计如表:并且从市场调研中总结得知:该基地的蔬菜C的种植面积一般是蔬菜B种植面积的2倍,生产基地要按照这个规律种植,才不至于滞销.现知道基地共有用地200亩,蔬菜A每亩产量为3吨,蔬菜B每亩产量为5吨,蔬菜C每亩产量为7吨.若设种植蔬菜B为x亩,基地假设把生产的蔬菜都能销售出去,其利润为y元.(1)求y与x之间的函数关系式;(2)根据市场行情,蔬菜A的种植不能多于50亩,求该蔬菜生产基地在这次种植中能获得的最大利润.23.有6张不透明的卡片,除正面写有不同的数字﹣1,2,,π,0,﹣外,其他均相同,将这6张卡片背面朝上洗匀后放在桌面上.从中随机抽取一张卡片记录数据后放回,重新洗匀后,再从中抽取一张卡片并记录数据.求两次抽取的数字之积是无理数的概率.24.如图,正方形ABCD接于⊙O,延长BA到E,使AE=AB,连接ED.(1)求证:直线ED是⊙O的切线;(2)连接EO交AD于F,若⊙O的半径为2,求FO的长.25.已知抛物线经过A(﹣4,0),B(0,﹣4),C(2,0)三点.(1)求抛物线的解析式;(2)若点M为第三象限内抛物线上一动点,点M的横坐标为m,△AMB的面积为S,求S关于m的函数关系式,并求S的最大值;(3)若点P是抛物线上的动点,点Q是直线y=﹣x上的动点,使得点P、Q、B、O的四边形为平行四边形,求Q的坐标.26.问题探究(1)请在图①的正方形ABCD的对角线BD是作一点P,使PA+PC最小;(2)如图②,点P为矩形ABCD的对角线BD上一动点,AB=2,BC=2,点E为BC边的中点,求作一点P,使PE+PC最小,并求这个最小值.问题解决(3)如图③,李师傅有一块边长为1000米的菱形ABCD采摘园,AC=1200米,BD为小路,BC的中点E为一水池,李师傅现在准备在小路BD上建一个游客临时休息纳凉室P,为了节省土地,使休息纳凉室P到水池E与大门C的距离之和最短,那么是否存在符合条件的点P?若存在,请作出的点P位置,并求出这个最短距离;若不存在,请说明理由.2016年陕西省西安市益新中学中考数学三模试卷参考答案与试题解析一.选择题1.计算:﹣1﹣2=()A.1 B.﹣1 C.﹣2 D.﹣3【考点】有理数的减法.【分析】根据有理数的减法运算进行计算即可得解.【解答】解:﹣1﹣2=﹣3,故选D.2.如图,由两个相同的正方体和一个圆锥体组成一个立体图形,其俯视图是()A.B.C.D.【考点】简单组合体的三视图.【分析】找到从上面看所得到的图形即可,注意所有的看到的棱都应表现在俯视图中.【解答】解:从几何体的上面看:可以得到两个正方形,右边的正方形里面有一个内接圆,故选:D.3.下列运算正确的是()A.(﹣2a)3=﹣6a3B.﹣3a2•4a3=﹣12a5C.﹣3a(2﹣a)=6a﹣3a2D.2a3﹣a2=2a【考点】单项式乘多项式;合并同类项;去括号与添括号;幂的乘方与积的乘方;单项式乘单项式.【分析】先根据同底数幂的乘法法则,幂的乘方,积的乘方,合并同类项分别求出每个式子的值,再判断即可.【解答】解:A、(﹣2a)3=﹣8a3;故本选项错误;B、﹣3a2•4a3=﹣12a5;故本选项正确;C、﹣3a(2﹣a)=6+﹣3a2;故本选项错误;D、不是同类项不能合并;故本选项错误;故选B.4.如图,在Rt△ACB中,∠ACB=90°,∠A=25°,D是AB上一点.将Rt△ABC沿CD折叠,使B点落在AC边上的B′处,则∠ADB′等于()A.40° B.35° C.30° D.25°【考点】三角形内角和定理;翻折变换(折叠问题).【分析】先根据三角形内角和定理求出∠B的度数,再由图形翻折变换的性质得出∠CB′D 的度数,再由三角形外角的性质即可得出结论.【解答】解:∵在Rt△ACB中,∠ACB=90°,∠A=25°,∴∠B=90°﹣25°=65°,∵△CDB′由△CDB反折而成,∴∠CB′D=∠B=65°,∵∠CB′D是△AB′D的外角,∴∠ADB′=∠CB′D﹣∠A=65°﹣25°=40°.故选:A.5.若正比例函数的图象经过点(﹣1,2),(﹣m,4﹣2m),则m的值为()A.﹣1 B.﹣2 C.2 D.1【考点】一次函数图象上点的坐标特征.【分析】根据点的坐标利用待定系数法即可求出正比例函数解析式,再根据一次函数图象上点的坐标特征即可得出关于m的一元一次方程,解之即可得出结论.【解答】解:设正比例函数解析式为y=kx(k≠0),将(﹣1,2)代入y=kx中,2=﹣k,解得:k=﹣2.∴正比例函数解析式为y=﹣2x.∵点(﹣m,4﹣2m)在正比例函数y=﹣2x的图象上,∴4﹣2m=2m,解得:m=1.故选D.6.如图,▱ABCD的对角线AC与BD相交于点O,AB⊥AC,若AB=4,AC=6,则BD的长是()A.8 B.9 C.10 D.11【考点】平行四边形的性质;勾股定理.【分析】利用平行四边形的性质和勾股定理易求BO的长,进而可求出BD的长.【解答】解:∵▱ABCD的对角线AC与BD相交于点O,∴BO=DO,AO=CO,∵AB⊥AC,AB=4,AC=6,∴BO==5,∴BD=2BO=10,故选:C.7.若正方形的边长为6,则其外接圆半径与内切圆半径的大小分别为()A.6,B.,3 C.6,3 D.,【考点】正多边形和圆.【分析】由正方形的边长、外接圆半径、内切圆半径正好组成一个直角三角形,从而求得它们的长度.【解答】解:∵正方形的边长为6,∴AB=3,又∵∠AOB=45°,∴OB=3∴AO==3,即外接圆半径为3,内切圆半径为3.故选:B.8.在平面直角坐标系中,把直线y=2x向左平移1个单位长度,平移后的直线解析式是()A.y=2x+1 B.y=2x﹣1 C.y=2x+2 D.y=2x﹣2【考点】一次函数图象与几何变换.【分析】根据“左加右减”的原则进行解答即可.【解答】解:由“左加右减”的原则可知,将直线y=2x向左平移1个单位所得的直线的解析式是y=2(x+1)=2x+2.即y=2x+2,故选C9.如图,在菱形ABCD中,∠A=60°,E、F分别是AB,AD的中点,DE、BF相交于点G,连接BD,CG.有下列结论:①∠BGD=120°;②BG+DG=CG;③△BDF≌△CGB;④S△ABD=AB2其中正确的结论有()A.1个B.2个C.3个D.4个【考点】菱形的性质;全等三角形的判定与性质;等边三角形的判定与性质.【分析】先判断出△ABD、BDC是等边三角形,然后根据等边三角形的三心(重心、内心、垂心)合一的性质,结合菱形对角线平分一组对角,三角形的判定定理可分别进行各项的判断.【解答】解:①由菱形的性质可得△ABD、BDC是等边三角形,∠DGB=∠GBE+∠GEB=30°+90°=120°,故①正确;②∵∠DCG=∠BCG=30°,DE⊥AB,∴可得DG=CG(30°角所对直角边等于斜边一半)、BG= CG,故可得出BG+DG=CG,即②也正确;③首先可得对应边BG≠FD,因为BG=DG,DG>FD,故可得△BDF不全等△CGB,即③错误;④S△ABD=AB•DE=AB•BE=AB•AB=AB2,即④正确.综上可得①②④正确,共3个.故选C.10.已知抛物线y=ax2+bx﹣2与x轴没有交点,过A(﹣、y1)、B(﹣3,y2)、C(1,y2)、D(,y3)四点,则y1、y2、y3的大小关系是()A.y1>y2>y3B.y2>y1>y3C.y1>y3>y2D.y3>y2>y1【考点】二次函数图象上点的坐标特征.【分析】由题意可知抛物线开口向下,对称轴为x==﹣1,然后根据点(﹣、y1)、C(1,y2)、D(,y3)离对称轴的远近可判断y1、y2、y3大小关系.【解答】解:由题意可知抛物线开口向下,对称轴为x==﹣1,∵|﹣1﹣(﹣)|<|1+1|<|+1|∴y1>y2>y3,故选A.二.填空题11.分解因式:x3y2﹣4x= x(xy+2)(xy﹣2).【考点】提公因式法与公式法的综合运用.【分析】先提取公因式x,再对余下的多项式利用平方差公式继续分解.平方差公式:a2﹣b2=(a+b)(a﹣b).【解答】解:x3y2﹣4x,=x(x2y2﹣4),=x(xy+2)(xy﹣2).14.如图,反比例函数y=(x>0)的图象经过平行四边形ABCO的顶点A和对角线的交点E,点A的横坐标为3,对角线AC所在的直线交y轴于(0,6)点,则函数y=的表达式为y=.【考点】平行四边形的性质;反比例函数图象上点的坐标特征.【分析】设A的坐标是(3,a),利用待定系数法即可求得直线AC的解析式,则C的坐标可求得,进而得到B的坐标,根据E是OB的中点,则E的坐标利用a可以表示出来,代入反比例函数解析式即可求解.【解答】解:设A的坐标是(3,a),则3a=k,即a=,设直线AC的解析式是y=mx+b,则,解得:,则直线AC的解析式是:y=x+6,令y=0,解得:x=,即OC=,则B的横坐标是:3+,则E的坐标是(+,),∵E在y=上,则(+)=k,又∵a=,∴(+)=k,解得:k=12,则反比例函数的解析式是:y=.故答案是:y=.15.如图,⊙O的半径为1cm,弦AB、CD的长度分别为cm,1cm,则弦AC、BD所夹的锐角α= 75 度.【考点】圆心角、弧、弦的关系;三角形的外角性质;勾股定理;垂径定理.【分析】根据勾股定理的逆定理可证△AOB是等腰直角三角形,故可求∠OAB=∠OBA=45°,又由已知可证△COD是等边三角形,所以∠ODC=∠OCD=60°,根据圆周角的性质可证∠CDB=∠CAB,而∠ODB=∠OBD,所以∠CAB+∠OBD=∠CDB+∠ODB=∠ODC=60°,再根据三角形的内角和定理可求α.【解答】解:连接OA、OB、OC、OD,∵OA=OB=OC=OD=1,AB=,CD=1,∴OA2+OB2=AB2,∴△AOB是等腰直角三角形,△COD是等边三角形,∴∠OAB=∠OBA=45°,∠ODC=∠OCD=60°,∵∠CDB=∠CAB,∠ODB=∠OBD,∴α=180°﹣∠CAB﹣∠OBA﹣∠OBD=180°﹣∠OBA﹣(∠CDB+∠ODB)=180°﹣45°﹣60°=75°.请从以下两个小题中任选一个作答,若多选,则按所选的第一题计分.12.在矩形ABCD中,AB=3,BC=4,BD的垂直平分线交AD于E,则AE的长为.【考点】矩形的性质;线段垂直平分线的性质.【分析】如图,连接BE.设AE=x,则DE=4﹣x.因为BD的垂直平分线交AD于E,所以EB=ED=4﹣x,在Rt△ABE中,根据AB2+AE2=BE2,列出方程即可解决问题.【解答】解:如图,连接BE.设AE=x,则DE=4﹣x.∵四边形ABCD是矩形,∴AD=CB=4,∠A=90°,∵BD的垂直平分线交AD于E,∴EB=ED=4﹣x,在Rt△ABE中,∵AB2+AE2=BE2,∴32+x2=(4﹣x)2,∴x=,∴AE=.故答案为.13.在 Rt△ABC中,∠ACB=90°,∠A=41°,BC=3,则AB的长为 1.97 .(用科学计算器计算,结果精确到0.01)【考点】计算器—三角函数;近似数和有效数字;计算器—数的开方.【分析】根据三角函数定义即可得到结论.【解答】解:∵∠ACB=90°,∠A=41°,BC=3,∴sin41°=,∴AB=BC•sin41°=3×0.656≈1.97,故答案为:1.97.三、解答题16.求不等式组的整数解.【考点】一元一次不等式组的整数解.【分析】先求出不等式组的解集,再求其整数解即可.【解答】解:解不等式①得:x>﹣2;解不等式②得:x≤;所以不等式组的解集为﹣2<x≤.整数解为:﹣1,0,1.17.先化简,再求值:,其中x=+1.【考点】分式的化简求值.【分析】原式括号中两项通分并利用同分母分式的减法法则计算,同时利用除法法则变形,约分得到最简结果,把x的值代入计算即可求出值.【解答】解:原式=•=﹣,当x=+1时,原式=﹣=﹣3+2.18.如图,已知线段a,c.求作Rt△ABC,使∠C=90°,AB=c,BC=a(尺规作图,保留作图痕迹).【考点】作图—复杂作图.【分析】先画线段AB=c,以线段c为直径作⊙O,再用点B为圆心,以线段a的长为半径作圆,角⊙O于点C,连接AC,则△ABC即为所求.【解答】解:如图,△ABC即为所求三角形.19.西安市地铁改变了人们的出行情况,也改变了学生到校的方式.小明同学就本校学生上学方式进行了一次统计调查,如图是他采集数据后绘制的两幅不完整的统计图.请你根据图中提供的信息回答以下问题:(A:步行,B:乘公交,C:坐地铁,D:骑自行车).(1)求被调查的学生人数;(2)补全两个统计图(3)若全校有1500人,估计该校学生上学坐地铁的人数,并根据调查结果,请你对西安开通地铁对学生上学的影响谈谈你的感想或建议.【考点】条形统计图;用样本估计总体;扇形统计图.【分析】(1)用乘车人数除以其所占比例即可得到该班的人数;(2)利用总人数乘以对应的百分比即可求得乘公交车和骑自行车的人数,从而补全统计图;(3)结合图上信息,提出符合实际意义的建议即可.【解答】解:(1)50÷10%=500名,即被调查的学生人数500名;(2)乘公交车的人数是:500×30%=150(人),骑自行车的人数是:500﹣50﹣150﹣200=100(人),坐地铁的占百分比: =40%,骑自行车的占百分比: =20%,条形统计图和扇形统计图如下:(3)估计该校学生坐地铁人数约有1500×=600人.从条形统计图和扇形统计图看出,坐地铁学生最多,速度快,节省时间,利于学习.20.如图,在正方形ABCD中,等边三角形AEF的顶点E、F分别在BC和CD上.(1)求证:CE=CF;(2)若等边三角形AEF的边长为2,求正方形ABCD的周长.【考点】正方形的性质;全等三角形的判定与性质;等边三角形的性质;等腰直角三角形.【分析】(1)根据正方形可知AB=AD,由等边三角形可知AE=AF,于是可以证明出△ABE≌△ADF,即可得出CE=CF;(2)连接AC,交EF与G点,由三角形AEF是等边三角形,三角形ECF是等腰直角三角形,于是可知AC⊥EF,求出EG=1,设BE=x,利用勾股定理求出x,即可求出BC的上,进而求出正方形的周长.【解答】(1)证明:∵四边形ABCD是正方形,∴AB=AD,∵△AEF是等边三角形,∴AE=AF,在Rt△ABE和Rt△ADF中,∵,∴Rt△ABE≌Rt△ADF(HL),∴BE=DF.又BC=DC,∴BC﹣BE=DC﹣DF,即EC=FC∴CE=CF,(2)解:连接AC,交EF于G点,∵△AEF是等边三角形,△ECF是等腰直角三角形,∴AC⊥EF,在Rt△AGE中,EG=sin30°AE=×2=1,∴EC=,设BE=x,则AB=x+,在Rt△ABE中,AB2+BE2=AE2,即(x+)2+x2=4,解得x1=,x2=(舍去)∴AB=+=,∴正方形ABCD的周长为4AB=2+2.21.高考英语听力测试期间,需要杜绝考点周围的噪音.如图,点A是某市一高考考点,在位于A考点南偏西15°方向距离125米的C处有一消防队.在听力考试期间,消防队突然接到报警电话,告知在位于C点北偏东75°方向的F点处突发火灾,消防队必须立即赶往救火.已知消防车的警报声传播半径为100米,若消防车的警报声对听力测试造成影响,则消防车必须改进行驶,试问:消防车是否需要改道行驶?请说明理由.(取1.732)【考点】解直角三角形的应用﹣方向角问题.【分析】首先过点A作AH⊥CF于点H,易得∠ACH=60°,然后利用三角函数的知识,求得AH的长,继而可得消防车是否需要改进行驶.【解答】解:如图:过点A作AH⊥CF于点H,由题意得:∠MCF=75°,∠CAN=15°,AC=125米,∵CM∥AN,∴∠ACM=∠CAN=15°,∴∠ACH=∠MCF﹣∠ACM=75°﹣15°=60°,∴在Rt△ACH中,AH=AC•sin∠ACH=125×≈108.25(米)>100米.答:消防车不需要改道行驶.22.某蔬菜生产基地经市场调查,对种植的A、B、C三种蔬菜的成本与售价情况统计如表:并且从市场调研中总结得知:该基地的蔬菜C的种植面积一般是蔬菜B种植面积的2倍,生产基地要按照这个规律种植,才不至于滞销.现知道基地共有用地200亩,蔬菜A每亩产量为3吨,蔬菜B每亩产量为5吨,蔬菜C每亩产量为7吨.若设种植蔬菜B为x亩,基地假设把生产的蔬菜都能销售出去,其利润为y元.(1)求y与x之间的函数关系式;(2)根据市场行情,蔬菜A的种植不能多于50亩,求该蔬菜生产基地在这次种植中能获得的最大利润.【考点】一次函数的应用;解一元一次不等式;一次函数的性质.【分析】(1)设种植蔬菜B为x亩,则种植蔬菜C为2x亩,种植蔬菜A为亩,根据总利润=种植A种蔬菜的利润+种植B种蔬菜的利润+种植C种蔬菜的利润即可得出y与x之间的函数关系式;(2)由蔬菜A的种植不能多于50亩即可得出关于x的一元一次不等式,解不等式即可得出x的取值范围,再根据一次函数的性质即可解决最值问题.【解答】解:(1)设种植蔬菜B为x亩,则种植蔬菜C为2x亩,种植蔬菜A为亩,根据题意得:y=3×+5××2x+7×x=﹣6100x+2400000.(2)∵200﹣3x≤50,解得:x≥50.∵在y=﹣6100x+2400000中k=﹣6100<0,∴当x=50时,y取最大值,最大值为2095000.答:该蔬菜生产基地在这次种植中能获得的最大利润为2095000元.23.有6张不透明的卡片,除正面写有不同的数字﹣1,2,,π,0,﹣外,其他均相同,将这6张卡片背面朝上洗匀后放在桌面上.从中随机抽取一张卡片记录数据后放回,重新洗匀后,再从中抽取一张卡片并记录数据.求两次抽取的数字之积是无理数的概率.【考点】列表法与树状图法;无理数.【分析】首先根据题意列出表格,然后由表格即可求得所有等可能的结果与两次抽取的数字之积是无理数的情况,再利用概率公式即可求得答案.【解答】解:列表得:π∵共有36种等可能的结果,两次抽取的数字之积是无理数的情况有18种,所以两次抽取的数字之积是无理数的概率==.24.如图,正方形ABCD接于⊙O,延长BA到E,使AE=AB,连接ED.(1)求证:直线ED是⊙O的切线;(2)连接EO交AD于F,若⊙O的半径为2,求FO的长.【考点】切线的判定;正方形的性质.【分析】(1)连接BD,则可知BD为直径,根据正方形的性质和已知条件可求得∠ADE=∠ODA=45°,可求得∠ODE=90°,可证得结论;(2)由勾股定理可求得正方形的边长,则可求得AE和AD,则可求得DE,在Rt△ODE中可求得OE的长,作OM⊥AB于M,根据平行线分线段成比例定理可证得EF=2OF,则可求得OF 的长.【解答】(1)证明:如图1,连接BD.∵四边形ABCD为正方形,AE=AB.∴AE=AB=AD,∠EAD=∠DAB=90°,∴∠EDA=45°,∠ODA=45°,∴∠ODE=∠ADE+∠ODA=90°,∴直线ED是⊙O的切线;(2)如图2,作OM⊥AB于M,∵O为正方形的中心,∴M为AB中点,∴AE=AB=2AM,AF∥OM,∴==2,∴EF=2FO,∵⊙O的半径为2,∴OD=2,BD=4,∴AD=AE==2,∴DE=4,在Rt△ODE中,由勾股定理可得OE==2,∴OF=OE=.25.已知抛物线经过A(﹣4,0),B(0,﹣4),C(2,0)三点.(1)求抛物线的解析式;(2)若点M为第三象限内抛物线上一动点,点M的横坐标为m,△AMB的面积为S,求S关于m的函数关系式,并求S的最大值;(3)若点P是抛物线上的动点,点Q是直线y=﹣x上的动点,使得点P、Q、B、O的四边形为平行四边形,求Q的坐标.【考点】二次函数综合题.【分析】(1)先假设出函数解析式,利用三点法求解函数解析式.(2)设出M点的坐标,利用S=S△AOM+S△OBM﹣S△AOB即可进行解答;(3)当OB是平行四边形的边时,表示出PQ的长,再根据平行四边形的对边相等列出方程求解即可;当OB是对角线时,由图可知点A与P应该重合.【解答】解:(1)设此抛物线的函数解析式为:y=ax2+bx+c(a≠0).将A(﹣4,0),B(0,﹣4),C(2,0)三点代入函数解析式得:,解得,所以此函数解析式为:y=x2+x=4.(2)如图所示:∵M点的横坐标为m,且点M在这条抛物线上,∴M点的坐标为:(m,),∴S=S△AOM+S△OBM﹣S△AOB=×4×(﹣m2﹣m+4)+×4×(﹣m)﹣×4×4=﹣m2﹣2m+8﹣2m﹣8=﹣m2﹣4m,=﹣(m+2)2+4,∵﹣4<m<0,当m=﹣2时,S有最大值为:S=﹣4+8=4.答:m=﹣2时S有最大值S=4.(3)设P(x, x2+x﹣4).当OB为边时,根据平行四边形的性质知PQ∥OB,且PQ=OB,∴Q的横坐标等于P的横坐标,又∵直线的解析式为y=﹣x,则Q(x,﹣x).由PQ=OB,得|﹣x﹣(x2+x﹣4)|=4,解得x=0,﹣4,﹣2±2.x=0不合题意,舍去.如图,当BO为对角线时,知A与P应该重合,OP=4.四边形PBQO为平行四边形则BQ=OP=4,Q横坐标为4,代入y=﹣x得出Q为(4,﹣4).由此可得Q(﹣4,4)或(﹣2+2,2﹣2)或(﹣2﹣2,2+2)或(4,﹣4).26.问题探究(1)请在图①的正方形ABCD的对角线BD是作一点P,使PA+PC最小;(2)如图②,点P为矩形ABCD的对角线BD上一动点,AB=2,BC=2,点E为BC边的中点,求作一点P,使PE+PC最小,并求这个最小值.问题解决(3)如图③,李师傅有一块边长为1000米的菱形ABCD采摘园,AC=1200米,BD为小路,BC的中点E为一水池,李师傅现在准备在小路BD上建一个游客临时休息纳凉室P,为了节省土地,使休息纳凉室P到水池E与大门C的距离之和最短,那么是否存在符合条件的点P?若存在,请作出的点P位置,并求出这个最短距离;若不存在,请说明理由.【考点】四边形综合题.【分析】(1)利用正方形的对称性直接连接AC即可;(2)作出点C关于BD的对称性,连接C'E交BD于P,进而判断出△CEC'是直角三角形,利用勾股定理即可求出;(3)直接连接AE交BD于P,再过点E作EF⊥AC,构造出直角三角形,再利用三角形的中位线求出EF,进而利用勾股定理求出CF,最后在Rt△AEF中利用勾股定理即可.【解答】解:(1)如图①,连接AC交BD于P,则AP+CP最小=AC;(2)如图②,作点C关于BD的对称点C'交BD于F,连接C'E交BD于P,则PE+PC最小=C'E.∵BD是矩形ABCD的对角线,∴CD=AB=2,∠BCD=90°,在Rt△BCD中,CD=2,BC=2,∴tan∠CBD===,∴∠CBD=30°,由对称知,CC'=2CF,CC'⊥BD,∴∠CFD=90°,∴∠BCF=60°,∠DCF=30°,在Rt△CDF中,CD=2,∠DCF=30°,∴CF=,∴CC'=2CF=2,∵点E为BC边的中点,∴CE=BC=,∴CF=CE,连接EF,∴△CEF是等边三角形,∴EF=CF=C'F,∴△CEC'是直角三角形,在Rt△CEC'中,CC'=2,CE=,∴C'E=3,∴PE+PC最小为3;(3)如图③,菱形ABCD的对角线相交于点O,∴OC=OA=AC=600,AC⊥BD,在Rt△BOC中,OB==800,过点E作EF⊥AC于F,∴EF∥OB,∵点E是BC的中点,EF=OB=400,∵CE=BC=500,根据勾股定理得,CF==300,∴AF=AC﹣CF=1200﹣300=900,连接AE交BD于P,即:PC+PE最小=AE,在Rt△AEF中,根据勾股定理得,AE==100,。
西安益新中学中考化学模拟卷
西安益新中学中考化学模拟卷一、选择题1.向用少量稀盐酸酸化的BaCl 2溶液中滴加由Na 2CO 3和Na 2SO 4组成的混合溶液,产生沉淀的量(m )与加入溶液的体积(V )之间的关系图正确的是A .AB .BC .CD .D2.不能正确对应变化关系的图像是( )A .A 图中横坐标既可以表示加入铁粉的质量,也可以表示加入部分变质的苛性钠质量B .B 图中纵坐标既可以表示溶质质量,又可表示溶液的导电性C .C 图中横坐标既可以表示反应时间,也可以表示加入二氧化锰质量D .D 图中纵坐标既可以表示溶剂质量,又可表示溶液质量 3.已知: 32322Fe(OH)Fe O +3H ΔO ,现将CO 气体与21.4g Fe (OH )3在密闭容器中加热一段时间后得到Fe 、Fe x O y 混合物12.8g ,将此混合物溶于100.0g 稀H 2SO 4恰好完全反应,产生0.2g H 2。
下列说法正确的是 A .生成CO 2和H 2O 共8.6g B .混合物中含5.6g 铁元素 C .Fe x O y 为Fe 2O 3D .该稀硫酸溶质的质量分数为19.6%4.如图所示,其中甲、乙、丙、丁、戊分别是铁、盐酸、氢氧化钙、二氧化碳、碳酸钠中的一种.图中相连的两圆表示相应物质能发生反应,已知乙是铁.下列说法错误的是A.五种物质中,只有铁是单质B.丙是盐酸C.戊是氢氧化钙D.甲与丁反应属于复分解反应5.用数形结合的方法表示某些化学知识直观、简明、易记.下列用数轴表示正确的是()A.不同物质的着火点:B.硫及其化合物与化合价的关系:C.50g19.6%的稀硫酸与足量的金属反应产生氢气的质量:D.物质形成溶液的pH:6.甲、乙、丙、丁均为初中化学常见的物质,它们之间的部分转化关系如图所示(部分反应物、生成物和反应条件已略去。
“——”表示物质之间能发生化学反应。
“―→”表示物质之间的转化关系)。
下列推论不正确...的是( )A.若甲是碳酸钙,则乙转化成丙的反应可以是放热反应B.若乙是最常用的溶剂,则丁可以是单质碳C.若甲是碳酸钠,乙是硫酸钠,则丁可以是氯化钡D.若丙是二氧化碳,丁是熟石灰,则丁可以通过复分解反应转化为乙7.甲、乙两种固体物质(不含结晶水)的溶解度曲线如图所示。
西安益新中学中考化学模拟卷
西安益新中学中考化学模拟卷一、选择题1.小明同学对所学部分化学知识归纳如下,其中完全正确的一组是A物质的分类B物质的检验和区别纯碱、胆矾、生石灰—盐类 煤、石油、天然气—化石燃料 可用灼烧闻味的方法检验羊毛和涤纶 燃着的木条区别氮气和二氧化碳 C概念的认识D 物质的性质和应用 能生成盐和水的反应是中和反应 含氧的化合物是氧化物洗涤剂乳化作用—去油污 石墨优良的导电性—作电极A .AB .BC .CD .D2.金属钠非常活泼,常温下在空气中易被氧化,也易与水反应。
现将5.4g 部分氧化的金属钠样品放入150g 16%的硫酸铜溶液中,充分反应后过滤,得到9.8g 蓝色滤渣。
(已知样品成分仅为Na 和Na 2O ,相关反应①222Na 2H O 2NaOH H +=+↑ ②22Na O H O 2NaOH +=),下列计算错误的是( ) A .最终所得溶液中存在两种溶质 B .最终所得溶液的质量为145.5g C .原混合物中钠元素质量为4.6gD .原混合物中钠和氧化钠的质量比为46: 313.甲、乙两种固体物质(不含结晶水)的溶解度曲线如图所示。
下列说法正确的是( )A .甲物质的溶解度大于乙物质的溶解度B .t 1℃时甲、乙两物质的溶液溶质质量分数一定相等C.t1℃时,甲、乙两物质各50 g分别加入100g水中,充分溶解,得到的溶液质量都是140gD.t2℃时,等质量甲、乙两种固体配制成饱和溶液时甲比乙需要的水多4.已知反应前后分子变化的微观示意图如下所示,下列说法错误..的是A.反应前后元素种类不变B.A是有机物,C、D是无机物C.点燃前要先检验A的纯度,防止爆炸D.此反应中A和B的化学计量数之比等于1:15.将铝和镁组成的混合物 10g 加入到 200g 稀盐酸中恰好完全反应后得到溶液 209g,再向溶液中加入足量的氢氧化钠溶液,最终生成沉淀的质量为()A.12g B.14.25g C.17.25g D.27g6.下列图象正确的是A.表示KMnO4加热制O2生成的MnO2的质量与时间的关系图B.表示CO还原CuO的实验中,试管内固体质量与时间关系图C.表示向Ca(NO3)2(含少量 HCl)溶液中滴加K2CO3溶液,沉淀量与K2CO3的加入量的关系图D.表示向足量的稀HCl中加入少量Fe,溶液质量与时间的关系图A.A B.B C.C D.D7.童童同学将一定量的氧化铜粉末加入到100g溶质的质量分数为14%的稀硫酸中,充分反应后固体全部消失,为了避免该废液排放造成污染,他又向废液中加入20g铁粉,充分反应后过滤,滤渣的质量为20g,加稀硫酸时所消耗的氧化铜质量是()A.8g B.10g C.12g D.14g8.下列除去物质中的少量杂质(括号内为杂质)的方法,正确的是()A.CO(CO2)——通过足量的灼热氧化铜B.MnO2粉末(KCl)——溶解、过滤、洗涤、干燥C.FeSO4溶液(CuSO4)——加入足量锌粉、过滤D.Na2SO4溶液(NaCl)——加入适量硝酸银溶液、过滤9.有一包固体粉末X,可能含有碳酸钙、硫酸铜、硫酸亚铁、锌粉,为确定固体粉末的成分,现取X进行下列实验,实验过程及现象如下图所示(不考虑水、稀盐酸的挥发),下列说法中正确的是( )A.若气体1为纯净物,则溶液2中可能含有三种阳离子B.若气体1为混合物,则溶液2中可能含有Fe2+C.若溶液1呈无色,则固体粉末X中不可能含有硫酸铜D.若溶液2呈浅绿色,则沉淀2不可能是纯净物10.将乙酸(CH3COOH)和葡萄糖(C6H12O6)溶于水得到混合溶液,测得溶液中氢元素的质量分数为a,则溶液中碳元素的质量分数为()A.1﹣9a B.1﹣8a C.12a D.8a11.有一包白色固体,可能含有FeCl3、 CaCO3、NaOH、Ba(OH)2、 BaCl2、 Na2SO4中的几种。
西安益新中学中考物理模拟卷
西安益新中学中考物理模拟卷一、选择题1.如图甲所示,用力F1拉物体A在水平面上做匀速直线运动,移动一段距离s,若借助如图乙所示装置用力F2拉物体A在同样的水平面上做匀速直线运动移动相同的距离s,下列说法正确的是()A.图乙中总功W总=F2s B.图乙中有用功W有=F1sC.图乙中额外功W额=F2s-F1s D.图乙中的机械效率η=12FF2.如图所示,电源电压保持不变,闭合开关S,当滑动变阻器滑片P向右移动时,关于电压表、电流表的示数变化情况,下列说法正确的是()A.电压表示数变大B.电压表示数变小C.电流表示数变大D.电流表示数变小3.下列说法正确的是()A.一个物体吸收热量其温度不一定会升高B.电动机正常工作过程中其线圈中不会产生感应电流C.一个物体只要受到力的作用,其运动状态一定会发生改变D.一个物体相对于另一个物体的距离保持不变,则二者一定是相对静止的4.无线电充是一种增加手机续航时间的方式,无线电充的技术原理:电流流过充电座的“送电线圈”产生磁场,当手机中的“受电线圈”靠近该磁场时就会产生感应电流,从而给手机电池充电,如图所示。
下列图中,与“受电线圈”处用到的实验原理相同的是()A.B.C.D.5.如图所示,某一型号的锁设置了三种打开方式:密码(S1)、特定指纹(S2)或应急钥匙(S3),三者都可以单独使电动机M工作而打开门锁,下列电路设计符合要求的是A.B.C.D.6.以下事例与物理知识对应的是()A.高压锅的原理﹣﹣﹣沸点与气压的关系B.用验钞机检验人民币的真伪﹣﹣﹣利用红外线使荧光物质发光C.吹电风扇感到凉爽﹣﹣﹣风扇转动降低了室温D.运动员打鼓用的力越大,鼓声越高﹣﹣﹣振幅越大,音调越高7.我国未来的航母将采用自行研制的电磁弹射器.电磁弹射器的弹射车与飞机前轮连接,并处于强磁场中,当弹射车内的导体通以强电流时,舰载机受到强大的推力而快速起飞.电磁弹射器工作原理与下列设备或用电器工作原理一致的是()A.B.C.D.8.小明家有额定电压相同的微波炉和电视机各一台,按照每度电0.55元的计费标准,将这两个用电器正常工作1h所用的电费绘制成了如图所示的柱状图,对小明家的这两个用电器,下列判断正确的是()A.微波炉正常工作时的电压大于电视机正常工作时的电压B.微波炉正常工作时的电流等于电视机正常工作时的电流C.微波炉正常工作时的电功率大于电视机正常工作时的电功率D.每月在微波炉上用的电费一定比在电视机上用的电费多9.下列物品中,通常情况下属于导体的是A.玻璃杯B.陶瓷碗C.铁锅D.塑料勺10.如图所示是某同学设计的家庭电路,电灯开关已断开.下列说法正确的是()A.灯泡和两孔插座是串联的B.试电笔接触M点,氖管不发光C.开关和三孔插座的连接都是错误的D.试电笔插入两孔插座的左孔,氖管发光11.一只小猫正在平面镜前欣赏自己的全身像,如图所示.此时它所看到的全身像应是图中的A.B.C.D.12.如图所示,防治新冠疫情的医护人员佩戴护目镜一段时间后,护目镜内会出现水雾。
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西安益新中学2017届(化学)第三次模拟试题
可能用到的相对原子质量:H 1- O 16-S 32- Zn 65-Cu 64-
一、选择题(本大题包括7个小题,每小题2分,共14分)每小题只有一个选项符合题意,将正确选项的序号填入括号内。
9.下列选项中物质的俗名、化学式、类别、用途完全对应的是() A .天然气4CH 有机物燃料 B .生石灰 CaO 氧化物补钙剂 C .小苏打3NaHCO 盐发酵粉 D .酒精25C H OH 碱溶剂
10.下列排序正确的是()
A .地壳中元素的含量O Si Fe Al
−−−−→由多到少
B .溶液的pH −−−−−−→汽水食水肥皂水
由大到小
C .硫元素的化合价224H S S H SO −−−−−→由高到低
D .溶解时放出的热量43NaOH NaCl NH NO −−−−−−−→由多到少
11.下列几种符号有关说法正确的是()
①2CO ②2O ③2Ca +④⑤23Na SO ⑥4ZnSO
A .①②中数字“2”表示的意义相同
B .③⑥中金属元素在化合物中的化合价相同
C .③④表示的是阳离子
D .⑤⑥中含有相同的原子团
12.如图是小俊用手势OK 表示初中常见化学反应中生成二氧化碳的不同方法,要求手指上的物质分别通过某种反应的基本类型直接生成二氧化碳(如图中的23H CO 、2O ),则物质X 一定不可能是()
A .4CH
B .3CaCO
C .C
D .CuO
13.屠呦呦带领科研团队研发的新型抗疟疾药一一青蒿素和双氢青蒿素,在全球抗击疟疾进程中,拯救了上百万人的生命,因此获得2015年诺贝尔生物医学奖.青蒿素化学式为15225C H O ,下列说法不正确的是() A .青蒿素属于无机物
B .青蒿素中氧元素的质量分数为28.4%
C .青蒿素中C 、H 、O 三种元素的原子个数比为15:22:5
D .利用化学提取和合成药物.以抑制细菌和病毒,保障人体健康
14.下列实验过程中与图象描述相符的一组是()
A .两份等质量、等溶质质量分数的双氧水
B .向一定质量的稀硫酸和氯化铜 溶液在有无2MnO 的情况下产生氧气
的混合溶液中加入氢氧化钠溶液
C .室温下,向一定质量的
D .向等质量的镁、锌中分别加入足量稀硫酸
饱和石灰水中加入氧化钙
15.某固体可能含有2CaCl 、24Na SO 、23Na CO 、3FeCl 、KCl 中的一种或几种,现对其进行如下实验: ①取少量固体于试管中,加适量蒸馏水,固体完全溶解成无色透明溶液;②取少量上述溶液,加过量稀硫酸,有气泡产生;③取②所得溶液少量,滴加2BaCl 溶液,产生白色沉淀.分析以上实验现象,对原固体组成的推断正确的是()
A .肯定有23Na CO 、24Na SO ;无3FeCl 、2CaCl ;可能有KCl
B .肯定有23Na CO ;无3FeCl 、2CaCl ;可能有KCl
C .肯定有23Na CO 、24Na SO ;无3FeCl ;可能有2CaCl
D .肯定有23Na CO ;无3FeCl 、KCl ;可能有2CaCl
二、填空题(本大题包括5个小题,共l8分)
16.(3分)凉皮、肉夹馍、牛羊肉泡馍是西安人非常喜爱的三种特色美食,请回答: (1)肉夹馍中富含__________(填一种有机营养素)
(2)牛羊肉泡馍一端上来就能闻到香味,原因是__________(填分子的一种特性) (3)盛过凉皮的餐具可用洗洁精清洗,这是利用了洗洁精的__________作用。
17.(3分)图为甲、乙、丙三种不含结晶水的固体物质的溶解度曲线。
(1)2t ℃时,甲、乙、丙三种物质的溶解度由小到大的顺序为__________。
(2)将2t ℃时接近饱和的丙溶液变成饱和溶液,下列方法不能达到目的是__________。
A .蒸发溶剂 B .降低温度
C .加溶质丙
D .升高温度
(3)当等质量甲的饱和溶液和乙的饱和溶液从2t ℃降温到1t ℃,对所得溶液的叙述正确的是__________
(填序号)
A.都是饱和溶液B.溶液质量:甲=乙
C.溶质质量分数:甲>乙D.溶剂质量:甲<乙
18.(4分)1926年的“联合制碱法”改进了国外的纯碱生产工艺,主要流程如图所示:
(1)“联合制碱法”制得的纯碱为__________.(填物质名称)
(2)如何取出从沉淀池中不断结晶析出的碳酸氢钠:__________(填操作名称)。
(3)该制碱过程中同时得到一种氮肥__________(填化学式),它不能与熟石灰混用的原因是
__________。
19.(3分)根据图中提供的信息,请回答下列问题:
(1)由A图可知.硅的相对原子质量为__________;
(2)B、C元素化学性质相似的原因是__________相同;
(3)C、E两种元素组成化合物的化学式为__________。
20.(5分)已知A I 均为初中常见的物质,其中组成A、C两种气体的元素相同,且C是常见的温室
气体,B是铁锈的主要成分,D是单质,F是硫酸盐,根据如图所示的转化关系(图中反应条件均己略去)回答下列问题:
(1)B的化学式为__________。
(2)写出反应①的化学方程式__________。
(3)绿色植物通过__________作用完成反应②,在此过程中能量的转化形式是__________。
三、实验探究题(本题有2小题,共13分)
21.(6)某校化学兴趣小组的同学在查阅资料时发现,
H和CO都具有还原性,工业上常用于冶炼金
2
属.该小组的同学为了探究
H的还原性,他们设计了如下装置进行实验探究。
2
请你帮助该小组回答下列有关问题:
(1)实验室中选择装置A用于制备气体的条件是__________。
(2)该小组的同学用浓盐酸和锌粒来制取氢气,则从A中出来的气体常含有__________(填化学式),
在探究氢气的还原性时必须除去这两种气体,以防对实验结果造成干扰,则装置C中盛放的是__________。
(3)在实验过程中可以观察到装置D中__________,且装置E中浓硫酸增重.写出D中发生反应的化学
方程式为__________。
22.(7分)工业上常用电解饱和食盐水的方法制取烧碱,某化学兴趣小组为了探究久置的工业烧碱的成分,进行了如下实验:
(1)取少量样品于烧杯中,向其中加入过量稀盐酸,观察到有气泡产生,说明样品中含有__________,
该反应的化学方程式为__________,接着又向烧杯中继续加入__________溶液,出现了白色沉淀,甲同学
立刻得出结论:样品中还含有氯化钠,乙同学对该结论提出了质疑,认为不一定含有氯化钠,理由是
__________。
(2)丙同学认为除了需要确认是否含有氯化钠外,还需要确认样品中是否含有氢氧化钠,于是,大家又
进行了以下实验:
①另取少量样品溶解于水,向其中加入过量硝酸钙溶液(呈中性),产生白色沉淀,然后过滤、洗涤;
②向滤液中加入足量稀硝酸,再滴入硝酸银溶液后产生白色沉淀;
③向滤渣中加少量水后滴入酚酞,溶液变红。
由此判断,滤渣中的物质是__________(填化学式)。
(3)根据以上实验事实,该样品中含有__________(填化学式)。
四、计算题(本大题包括1个小题,共5分)
23.(5分)合金的种类很多,用途非常广泛,黄铜是铜和锌的合金,它可以用来制造机器和电器的零件等.化学兴趣小组的同学欲测定实验室中某铜样品中铜的质量分数(不考虑黄铜中的其他杂质),请你参
与他们的探究过程。
称量20g粉末状黄铜样品放入烧杯中,量取60mL稀硫酸分三次加到其中,每次充分反应后,测定生成氢
气的质量,实验数据如表:
(1)m的数值__________。
(2)此黄铜样品中铜的质量分数是多少?(写出计算过程)
(3)所加稀硫酸溶液的溶质质量分数?(该温度下稀硫酸密度为1.066g/ml,计算结果保留至0.01%)。