1. What do you think ____ solve the problem?
A. you can do
B. can you do
C. you can do to
D. can you do to
2. In the past he often made his sister ____, but now he is often made ____ by his sister.
A. to cry; to cry
B. cry; cry
C. to cry; cry
D. cry; to cry
3. The teacher told us that the sun ____ in the east.
A. rises
B. rose
C. raises
D. raised
4. He lives in a village ____ there are a lot of trees.
A. there
B. where
C. that
D. which
5. He ____ Alice for ten years.
A. married to
B. has married to
C. has married
D. has been married to
6. We need fifteen more people ____ our team to do the job.
A. but
B. except
C. as well
D. besides
7. They won't allow us ____ at this beach.
A. swimming
B. to swim
C. swam
D. swim
8. Is this factory ____ you visited last week?
A. that
B. where
C. the one
D. in which
9. The reason ____ he was absent from the meeting was ____ his car broke down on the way.
A. that; because
B. why; that
C. that; that
D. for; that
10. Is the river ____ through that town very large?
A. which flows
B. flows
C. that flowing
D. whose flows
11. The teacher told me that the students I wanted to see were seen ____ football on the playground just now.
A. playing
B. to be playing
C. play
D. to play
12. The red rose is the only one ____ I real like.
A. which
B. who
C. that
D. whom
13. All the apples ____ fell down were eaten by the pigs.
A. those
B. which
C. what
D. that
14. Don`t forget the day ____ you were received into the Youth League.
A. when
B. that
C. at which
D. where
15. I prefer ____ at home to ____ outside.
A. staying, playing
B. to stay, play
C. staying, play
D. to stay, playing
16. The box is ____ what I saw in the shop.
A. same as
B. the same like
C. the same that
D. the same as
17. The pen ____ she writes letters is broken.
A. which
B. that
C. with which
D. by which
18. Would you like to ____ us in our discussion.
A. take part in
B. join
C. taking part in
D. joining
19. I'm sure the red team will ____ the game.
A. win
B. beat
C. defeat
D. succeed
20. Ahead of me I saw a woman ____ I thought was my aunt.
A. who
B. whom
C. of whom
D. whose
21. ____ your help, everything in the room is in good order now.
A. Since
B. Because
C. thanks for
D. Thanks to
22. He is known to the world and has a lot of friends ____.
A. in and out of abroad
B. at home and abroad
C. at home and at abroad
D. in home and out of abroad
23. --Are you going there with them? --If you go, ____.
A. I also go
B. so do I
C. so I will
D. so will I
24. --The flower is beautiful. --____.
A. So is it
B. So it is
C. It is so
D. So it is
25. The number of people invited ____ fifty, but a number of them ____ absent for different reasons.
A. were; was
B. was; was
C. was; were
D. were; were
26. We haven`t had any success ____.
A. before long
B. so long
C. by far
D. so far
27. Travellers ____ our country enjoy the beautiful sights in Beijing, Hangzhou and many other places of interest.
A. for
B. to
C. till
D. by
28. If a man ____ succeed, he must work as hard as he can.
A. will
B. should
C. is going to
D. is to
29. --I am sorry I didn`t do a good job.
--Never mind. ____ you have tried your best.
A. Above all
B. In all
C. At all
D. After all
30. The best way to make sure that you can keep fit is to ____ healthy eating habits.
A. find
B. create
C. develop
D. prepare
31. We have spent ____ money on English books.
A. a great deal of
B. a good many
C. a plenty of
D. a number of
32. ____ met, it won`t be easily forgotten.
A. If only
B. When if
C. Once
D. Once you were
33. The differences ____ these two pictures ____ colour are easy to see.
A. in, of
B. from, of
C. between, in
D. of, in
34. You should put ____ “s” at the end of this word.
A. a
B. /
C. an
D. the
35. --What`s ____ population of China?
--China has ____ population of 1.2 billion.
A. a; the
B. the; a
C. /; /
D. the; the
36. It`s ____ here. We can`t work long hours here.
A. very much cold
B. much cold
C. much too cold
D. too much cold
37. ____ terrible weather we`ve been having these days!
A. How a
B. What a
C. How
D. What
38. --Have you decided when ____?
--Yes, tomorrow morning.
A. will you leave
B. to be leaving
C. are you leaving
D. to leave
39. The song ____ My heart will go on is liked by the young people.
A. call
B. calling
C. called
D. to call
40. Train services are now back to ____ after three days of typhoon.
A. usual
B. common
C. ordinary
D. normal
41. He is the best ____ English in our class. A. at B. in C. for D. to
42. The policeman caught hold of the thief and hit him ____ the head.
A. in the
B. on his
C. on the
D. in his
43. Did John hit Bob ____ eye?
A. in the
B. on the
C. in his
D. on his
44. There is ____ interesting ____ today`s newspaper.
A. anything … in
B. nothing … in
C. something … on
D. nothing … on
45. Has your teacher given you any advice ____ your study?
A. in
B. to
C. on
D. with
46. It`s bad manners to laugh ____ others when they are ____ trouble.
A. at, in
B. over, at
C. with, on
D. to, with
47. Betty doesn`t have enough money to buy that coat. It`s very ____.
The price is too ____.
A. high, high
B. expensive, expensive
C. expensive, high
D. high, expensive
48. This kind of glasses manufactured by experienced craftsmen ____ comfortably.
A. wearing
B. wear
C. wears
D. is worn
49. The diamond is ____.
A. very valuable
B. of great value
C. great value
D. A or B
50. Behind the dancer there was a woman ____ a large diamond ring.
A. carrying
B. dressing
C. wearing
D. having
51. The young teacher who has a ____ face can make his classes ____ and interesting.
A. lovely, lively
B. lovely, lovely
C. likely, friendly
D. uglily, lively
52 They were still ____ their friends after their child`s long illness.
A. in debt to
B. in the debt to
C. in debt with
D. in the debt with
53. ____, my brother passed the exam.
A. To my great joy
B. To my great surprised
C. With my joy
D. With my surprise
54. I am all tears, ____, I am listening to you with all attention.
A. in another words
B. in the other words
C. with other words
D. in other words
55. He started early ____ he could get there before nine.
A. in order that
B. because
C. so as to
D. in order to
56. As you know, whether the person will be elected president is matter of ____ interest.
A. general
B. common
C. ordinary
D. mostly
57. I ____ by his story that he made up.
A. was taken on
B. was taken out
C. was taken in
D. am taken in
58. He didn`t go into detail on the subject, he spoke ____.
A. in general
B. in particular
C. in common
D. in short
59. We designed the machine ____ the purpose ____ production.
A. for, of increasing
B. with, of increasing
C. for, to increase
D. A or B
60. Hospital doctors don`t go out very often as their work ____ all their time.
A. takes away
B. takes in
C. takes over
D. takes up
61. We offered him our congratulation ____ his passing the entrance exam.
A. on
B. for
C. with
D. at
62. My mother ____ classical music while I am ____ rock music.
A. is fond of, in
B. likes, like
C. is interested in; into
D. interests; enjoy
63. We each ____ strong points and each of us on the other hand ____ weak points.
A. have, have
B. has, have
C. has, has
D. have, has
64. He is one of the students who, I am sure, always do ____ best.
A. his
B. one`s
C. my
D. their
65. The police ____ determined to bring back the missing boy when his family ____
almost given hope.
A. is, has
B. are, have
C. are, has
D. is, have
66. More than one girl ____ late for class this morning.
A. are
B. is
C. was
D. were
67. Many a student ____ in the exam.
A. have failed
B. had been failed
C. has failed
D. will be failed
68. What he says and what he does ____.
A. is not agree
B. are not agree
C. does not agree
D. do not agree
69 Not only politics but also English is important. In other words, ____ is important.
A. English, as well as politics
B. English as well as politics
C. both politics and English
D. politics, as well as English
70. It was at the very beginning ____ Mr.Smith made a decision ____ we should send for a doctor.
A. what, that
B. that, which
C. which, that
D. that, that
71. On the way back home from the ball, she suddenly found her necklace ____.
A. missed
B. losing
C. gone
D. be stolen
72. He didn't go to the party not ____ the time but ____ he was ill.
A. because of, because
B. because, because
C. because, because of
D. because of, because of
73. The teacher gave me a piece of paper ____.
A. to write on
B. to be written on
C. to write in
D. to be written
74. I can`t believe he could jump ____ high.
A. very much
B. such
C. that
D. this
75. --The boys are not doing a good job at all, are they? --____.
A. I guess not so
B. I don`t guess so
C. I don`t guess
D. I guess not
76. The magazine is ____ reading, so he advised me ____ it.
A. well worth; to buy
B. very worth; buying
C. worthing, buying
D. worthy, to buy
77. She is on a special ____ to lose ____ weight.
A. food; her
B. food; / D. diet; her D. diet; /
78. Jenny ____ a rich man. She has ____ him for 5 years.
A. married with; married with
B. married; married
C. married to; been married
D. married; been married to
79. I am ____ hungry. Give me ____ of milk.
A. a bit; a little
B. not a little; a bit
C. little; a lit
D. not a little; a little
80. A good friend is someone ____ makes you ____.
A. which; happy
B. who; happily
C. who; happy
D. whose; happily
81. He was about ____ when suddenly the telephone rang.
A. to leave
B. to starting
C. leaving
D. setting off
82. This task is ____ difficult for us. We need ____ people.
A. much too; another three
B. too much; other three
C. much too; more three
D. too much; three more
83. He seems to ____ to Jane. He knows her well.
A. have been introduced
B. be introduced
C. have introduced
D. introduced
84. This is a film ____ Spielberg used real actors instead of stunt men.
A. which
B. whose
C. in which
D. of which
85. He ____ much of his success and happiness ____ his wife and children.
A. thanks; to
B. owes; to
C. owns; to
D. thinks; highly of
86. He will never forget the days ____ he spent with you in Japan.
A. when
B. that
C. on which
D. in which
87. Which sentence is incorrect?
A. I feel interested in classical music
B. I take interest in classical music
C. I am not into classical music
D. I don`t fond of classical music
88. No one likes ____ in ____ public.
A. to be laughed at; the
B. laughing at; the
C. being laughed at; /
D. to be laughing at; /
89. We are considering ____ a sports meet next month.
A to hold
B holding
C to be held
D as holding
90. Which sentence is incorrect?
A. He devoted himself to the work of children`s health care.
B. He is devoted to his work.
C. He devoted all his life to work hard in people`s interests.
D. He is determined to make more money for his family.
91. He doesn`t like classical music and ____ I.
A. so do
B. nor do
C. or do
D. nor am
92. Friends should ____ happiness and sorrow ____ each other.
A. share, with
B. solve, with
C. share, from
D. share, to
93. --I missed the first part of the film .It was really a pity.
--You ____ home half an hour earlier.
A. should have left
B. must have left
C. should leave
D. must leave
94. The storm died away at last with the golden waves ____ the shore in peace.
A. beaten
B. beat
C. to beat
D. beating
95. The whites are ____ holiday ,but I don`t know where they have gone ____ their holidays.
A. in, for
B. on, for
C. for, in
D. at, on
96. The river ____ are covered with trees is very long.
A.which banks
B. of which banks
C. whose the banks
D. the banks of which
97. She likes to use words ____ clear to her.
A. of which the meaning
B. of which meaning
C. whose of meaning
D. meaning of which
98. The price of this washing machine has been increased ____ 15%.
A. up
B. to
C. by
D. from
99. ____ someone`s health, you raise your glass.
A. Drink to
B. To drink to
C. If you drink
D. If drink to
100. Please ____ me about the interview ____ I forget.
A. remind; in case
B. remember; in case
C. remember, in case of
D. remind of; in case of
参考答案:
1-5 C D A B D 6 -10 D B C B A 11-15 A C D A A 16-20 D C B A A
21-25 D B D B C 26-30 D B D D C 31-35 A C C C B 36-40 C D D C D
41-45 B C A B C 46-50 A C C D C 51-55 A A A D A 56-60 A C A D D
61-65 A C D D B 66-70 C C D B D 71-75 C A A C D 76-80 A D D B C
81-85 A A A C B 86-90 B D C B C 91-95 B A A D B 96-100 D A C B A
一、二次函数真题与模拟题分类汇编(难题易错题) 1.已知二次函数的图象以A(﹣1,4)为顶点,且过点B(2,﹣5) (1)求该函数的关系式; (2)求该函数图象与坐标轴的交点坐标; (3)将该函数图象向右平移,当图象经过原点时,A、B两点随图象移至A′、B′,求△O A′B′的面积. 【答案】(1)y=﹣x2﹣2x+3;(2)抛物线与x轴的交点为:(﹣3,0),(1,0)(3)15. 【解析】 【分析】(1)已知了抛物线的顶点坐标,可用顶点式设该二次函数的解析式,然后将B 点坐标代入,即可求出二次函数的解析式; (2)根据函数解析式,令x=0,可求得抛物线与y轴的交点坐标;令y=0,可求得抛物线与x轴交点坐标; (3)由(2)可知:抛物线与x轴的交点分别在原点两侧,由此可求出当抛物线与x轴负半轴的交点平移到原点时,抛物线平移的单位,由此可求出A′、B′的坐标.由于△OA′B′不规则,可用面积割补法求出△OA′B′的面积. 【详解】(1)设抛物线顶点式y=a(x+1)2+4, 将B(2,﹣5)代入得:a=﹣1, ∴该函数的解析式为:y=﹣(x+1)2+4=﹣x2﹣2x+3; (2)令x=0,得y=3,因此抛物线与y轴的交点为:(0,3), 令y=0,﹣x2﹣2x+3=0,解得:x1=﹣3,x2=1, 即抛物线与x轴的交点为:(﹣3,0),(1,0); (3)设抛物线与x轴的交点为M、N(M在N的左侧), 由(2)知:M(﹣3,0),N(1,0), 当函数图象向右平移经过原点时,M与O重合,因此抛物线向右平移了3个单位, 故A'(2,4),B'(5,﹣5), ∴S△OA′B′=1 2 ×(2+5)×9﹣ 1 2 ×2×4﹣ 1 2 ×5×5=15. 【点睛】本题考查了用待定系数法求抛物线解析式、函数图象与坐标轴交点、图形面积的
1、(10%)用浓盐酸配制一定溶质质量分数的稀盐酸,实验时必不可少的一组仪器是 A、量筒、烧杯、漏斗、玻璃棒 B、托盘天平、玻璃棒、药匙、烧杯 C、托盘天平、玻璃棒、量筒、烧杯 D、玻璃棒、量筒、烧杯、胶头滴管 2、(12%)下列说法符合质量守恒定律的是 A、50g高锰酸钾加热充分反应后,剩余固体的质量小于高锰酸钾的质量 B、100g冰溶解后得到相同质量的水 C、10g食盐完全溶解在50g水中,得到60g食盐溶液 D、一杯水暴露在空气中一段时间后水分蒸发了,质量减少了 3、(15%)在硫酸铜、硫酸锌和稀硫酸的混合溶液中,加入一定量的铁粉,使之充分反应后,铁有剩余,过滤。则滤液中一定没有的溶质是,所得固体残渣中一定含有。(共2分) 4、(21%)下列物质中属于纯净物的是 A、洁净的食盐水 B、冰水混合物 C、净化后的空气 D、高锰酸钾完全分解后的剩余物 5.(23.1%)现有Fe、CuO、MgCl2、Ca(OH)2、稀H2SO4等五种物质,在常温下它们两两相互发生的化学反应有 A.7个 B.6个 C.5个 D.4个 6.(23.1%)向下表的甲物质中逐滴加入相应的乙溶液至过量,反应过程中生成气体或沉淀的质量与加入乙的质量关系,能用下图所示曲线表示的是 A.①② B.②④ C.③④ D.④ 7.(25%)实验室里将白磷放在水里保存,据此对白磷性质作出如下推测,不准确的是 A.它易与氧气反应 B.它遇水不反应 C.它难溶于水 D.它比水重 8、(32%)不能说明分子间有间隔的是 A、物质的热胀冷缩现象 B、食盐溶解在水中 C、食盐和蔗糖混合均匀 D、等质量的氧气和液氧,氧气体积比液氧大 9、(35%)在①碘酒②糖水③70%的酒精④稀硫酸等几种溶液中,溶剂是同一种物质的是 A、①③ B、②④ C、①②③ D、②③④ 10、(37.5%)(A~D都是初中化学中的常见物质,且有如图所示转化关系(反应条件、其他反应物及 多余产物均已略去)。 请写出下列物质的化学式: A B C D A
2015年最新中考科学:电学部分(难题、易错题)汇编 (考试内容:电流与电路、电压与电阻、欧姆定律、电功率、电与磁、生活用电) 一、选择题(每题2分,共50分) 1.如图所示,通草球甲、乙相互排斥,甲、丙相互吸引,如果已知甲带正电,那么乙、丙的带电情况是() A.乙带负电,丙带正电 B.乙带正电、丙带正电 C.乙带负电,丙带负电或不带电 D.乙带正电、丙带负电或不带电 2.由欧姆定律I=U/R变形可得R=U/I;下列说法正确的是() A.导体电阻跟它两端的电压成正比B.导体电阻跟通过它的电流成反比C.导体电阻跟通过的电流和它两端电压无关D.导体电压跟通过它的电流成正比 3.如图所示电路,下列分析正确的是() A.只闭合S1时,L2发光、L1不发光,A2测L2电流 B.只闭合S2时,L1发光、L2不发光,A1测L1电流 C.闭合S1、S2时,L1、L2并联,A2测L2电流 D.闭合S1、S2时,L1、L2串联,A1、A2示数相等 4.在探究串联电路电压关系实验中,科学实验小组按如图所示的电路测得V的示数是3.8V,V1的示数是2.3V,V2的示数应为() A.1.5V B.3.8V C.2.3V D.6.1V 第4题图第5题图第6题图 5.如图所示,当开关S闭合后,下列说法正确的是() A.灯L1与灯L2是串联,且灯L1被短路B.电压表可测出灯L1两端的电压 C.电流表A1测的是灯L1的电流D.电流表A2测的是灯L1的电流 6.灯泡L上标有“2.5V”的字样,它的电阻随它两端电压的变化关系如图所示,下列说法中正确的是() A.灯泡L的额定电流是0.2A B.灯泡L正常发光时的电阻是10ΩC.灯泡L的额定功率是6.25W D.灯丝的电阻随电压的增大而减小7.关于“12V 4W”的小灯泡L1和“9V 3W”的小灯泡L2,下列说法正确的是()A.L l和L2正常工作时的电阻一样大 B.L l和L2串联在一起使用时,两灯消耗的功率一样多 C.L l和L2并联在一起使用时,两灯消耗的功率一样多 D.L2串联一个9Ω的电阻接在12V电路中,也能正常发光 8.如图所示,甲、乙、丙三个密闭容器中密封着等量的空气,U型管中液面高度的变化反映密闭空气温度的变化。三个容器中的电阻丝串联起来接到电源两端,其中在丙容器的外部,将一个电阻和这个容器内的电阻并联。通电一段时间后,U型管中两侧的液面高
一、中考初中化学除杂分离和提纯 1.下列除去杂质的方法中,不正确的是() A.①②B.②③C.③④D.②④ 【答案】D 【解析】 【分析】 【详解】 ①氯化钠易溶于水,泥沙难溶于水,可采取加水溶解、过滤、蒸发的方法进行分离除杂,故选项所采取的方法正确; ②二氧化碳能与氢氧化钠固体反应生成碳酸钠和水,氢氧化钠固体具有吸水性,不但能把杂质除去,也会把原物质除去,不符合除杂原则,故选项所采取的方法错误; ③铁粉能与CuSO4反应生成硫酸亚铁和铜,再过滤除去不溶物,能除去杂质且没有引入新的杂质,符合除杂原则,故选项所采取的方法正确; ④Na2CO3能与过量的Ca(OH)2溶液反应生成碳酸钙沉淀和氢氧化钠,能除去杂质但引入了新的杂质氢氧化钙,不符合除杂原则,故选项所采取的方法错误,故②④方法不正确,故选D。 【点睛】 本题为除杂题,是中考的重点,也是难点,解决除杂问题时,抓住除杂的必需条件(加入的试剂只与杂质反应,反应后不能引入新杂质)是正确解题的关键。 2.除去下列物质中混有的杂质所用试剂和操作方法均正确的是( )
A.A B.B C.C D.D 【答案】B 【解析】 【分析】 除杂(提纯),是指除去杂质,同时被提纯物质不得改变。 【详解】 A、氢氧化钠和硫酸铜反应生成氢氧化铜和硫酸钠,引入了硫酸钠杂质,故A不正确; B、铁粉与足量稀硫酸反应生成硫酸亚铁溶液和氢气,铜不能与稀硫酸反应,再过滤、洗涤、干燥,能除去杂质且没有引入新的杂质,符合除杂原则,故B正确; C、石灰水吸收二氧化碳的能力较弱,将气体依次通过盛有石灰水、浓硫酸的洗气瓶不能除去杂质,故C不正确; D、二氧化碳不能与氯化钙溶液反应,故D不正确。故选B。 【点睛】 除杂条件:①加入的试剂只能与杂质反应,不能与原物质反应;②反应后不能引入新的杂质。 3.下表中,除去物质所含少量杂质的方法和反应类型归类均正确的是 A.A B.B C.C D.D 【答案】A 【解析】
一、锐角三角函数真题与模拟题分类汇编(难题易错题) 1.某地是国家AAAA 级旅游景区,以“奇山奇水奇石景,古賨古洞古部落”享誉巴渠,被誉为 “小九寨”.端坐在观音崖旁的一块奇石似一只“啸天犬”,昂首向天,望穿古今.一个周末,某数学兴趣小组的几名同学想测出“啸天犬”上嘴尖与头顶的距离.他们把蹲着的“啸天犬”抽象成四边形ABCD ,想法测出了尾部C 看头顶B 的仰角为40,从前脚落地点D 看上嘴尖A 的仰角刚好60,5CB m =, 2.7CD m =.景区管理员告诉同学们,上嘴尖到地面的距离是3m .于是,他们很快就算出了AB 的长.你也算算?(结果精确到0.1m .参考数据:400.64400.77400.84sin cos tan ?≈?≈?≈,,.2 1.41,3 1.73≈≈) 【答案】AB 的长约为0.6m . 【解析】 【分析】 作BF CE ⊥于F ,根据正弦的定义求出BF ,利用余弦的定义求出CF ,利用正切的定义求出DE ,结合图形计算即可. 【详解】 解:作BF CE ⊥于F , 在Rt BFC ?中, 3.20BF BC sin BCF ?∠≈=, 3.85CF BC cos BCF ?∠≈=, 在Rt ADE ?E 中,3 1.73tan 3AB DE ADE = ==≈∠, 0.200.58BH BF HF AH EF CD DE CF ∴+=﹣=,==﹣= 由勾股定理得,22BH AH 0.6(m)AB =+≈, 答:AB 的长约为0.6m .
【点睛】 考查的是解直角三角形的应用﹣仰角俯角问题,掌握仰角俯角的概念、熟记锐角三角函数的定义是解题的关键. 2.如图,AB是⊙O的直径,点C,D是半圆O的三等分点,过点C作⊙O的切线交AD的延长线于点E,过点D作DF⊥AB于点F,交⊙O于点H,连接DC,AC. (1)求证:∠AEC=90°; (2)试判断以点A,O,C,D为顶点的四边形的形状,并说明理由; (3)若DC=2,求DH的长. 【答案】(1)证明见解析; (2)四边形AOCD为菱形; (3)DH=2. 【解析】 试题分析:(1)连接OC,根据EC与⊙O切点C,则∠OCE=90°,由题意得 ,∠DAC=∠CAB,即可证明AE∥OC,则∠AEC+∠OCE=180°,从而得出 ∠AEC=90°; (2)四边形AOCD为菱形.由(1)得,则∠DCA=∠CAB可证明四边形AOCD是平行四边形,再由OA=OC,即可证明平行四边形AOCD是菱形(一组邻边相等的平行四边形是菱形); (3)连接OD.根据四边形AOCD为菱形,得△OAD是等边三角形,则∠AOD=60°,再由 DH⊥AB于点F,AB为直径,在Rt△OFD中,根据sin∠AOD=,求得DH的长. 试题解析:(1)连接OC,
潍坊五中2011中考复习之易错题精选 1.2011年央视《每周质量报告》的3·15特别节目曝光:河南生猪主产区采用违禁药品瘦肉精,有毒猪肉流向双汇分公司。“瘦肉精“的化学式C12H19Cl3N2O,则下列有关瘦肉精的说法中不正确的是 A、瘦肉精分子中含有氮分子 B.瘦肉精由碳、氢、氧、氯、氮五种元素组成 C.每个瘦肉精分子由37个原子构成 D.瘦肉精中质量分数最大的是碳元素 2.分类是学习和研究化学物质及其变化的一种常用的基本方法。现有药品硫酸铝,它与下列哪组属于同一类物质 A.盐酸、硫酸B、氯化钠、碳酸钾 C.二氧化碳、四氧化三铁 D.氢氧化铝、氢氧化钠 3.从图所示的两种微粒结构示意图中,所获取信息不正确的是 A、它们属于同种元素B.它们的核外电子层数相同 C.它们的核外电子数相同D.①表示阴离子,②表示原子 4.下列各项不随水量的变化而变化的是 A.溶液中溶质的质量分数B、物质的溶解度 C.电解水生成的氢气和氧气D.酸溶液的pH 5.现有t℃时的硫酸铜饱和溶液,下列有关叙述违背客观事实的是 A.加入一定量的硝酸铵固体后,固体溶解,并使溶液温度下降 B、加入一定量的水后,溶质质量变小 C.加入一定量的水后,硫酸铜溶解度不变,溶液变成不饱和溶液 D.放入一根铁丝后,铁丝表面有亮红色物质析出,说明铁比铜活泼 6.某同学对下列四个实验都设计了两种方案,其中方案1合理、方案2不合理的是 选项 A. B、 C. D. 实验目的除去氢氧化钠中 少量的碳酸钠 清洗铁制品 表面的铁锈 鉴别氯化钠 溶液和稀盐酸 检验一氧化碳中是否 混有二氧化碳气体 方案1 加水溶解加适量稀盐酸加锌粒点燃 方案2 加稀硫酸用水洗涤加石蕊溶液通入澄清石灰水7.下列实验对应的图像正确的是 A.将等质量的镁和铝分别与足量的盐B.向pH=2的盐酸 中滴加过量的氢 C、向盐酸和氯化铁的 混合溶液中加入过量 D.向pH=12的氢 氧化钠溶液中加水 酸反应氧化钠溶液的氢氧化钠溶液稀释 8.下列各组元素的原子结构示意图中,具有相似化学性质的一组元素是 +10 2 8 +8 2 6 2 8 8 +18 2 8 2 +12 +2 2 +9 2 7 2 8 1 +11 +2 2 A. 和 B. 和 C.和 D. 和 9.小明同学对下列4个实验都设计了两种方案,其中两种方案均合理的是 选项实验目的方案1 方案2 A. 除去氢氧化钠中少量的碳酸钠加水溶解加稀硫酸 B. 清洗铁制品表面的铁锈加稀盐酸用水洗涤 C、鉴别氯化钠溶液和稀盐酸加锌粒加石蕊试液 D. 检验一氧化碳中是否混有少量二氧化碳点燃通入澄清石灰水 10.下列各组物质在水溶液中能够共存,而且加入酚酞显红色的是() A.NaOH 、CuSO4、H2SO4B、NaCl、Na2SO4、Na2CO3 C.NaCl、Ba(NO3)2、HCl D.NH4NO3、NaOH、Na2SO4 11.下列各组物质的溶液混合后,不能发生反应的是() A、NaCl和H2SO4B.NaOH和HCl C.Na2CO3和H2SO4D.AgNO3和NaCl 12.下列除杂试剂和方法使用错误的是 选项物质(括号内为杂质)除杂试剂和方法 A.Cu(Fe2O3)加入稀硫酸,过滤 B.H2(水蒸气)通过浓硫酸,洗气 C.NaOH溶液(Na2CO3)加入石灰水,过滤 D、CaO(CaCO3)加入稀盐酸,过滤 13.除去下列各物质中的少量杂质,所选用的试剂、方法均正确的是(B)
一、中考初中化学综合题 1.铁及其合金是日常生活最常用的金属材料,用途非常广泛。请回答下列问题: (1)如图是一包烤花生的图片,袋内的脱氧剂对食品保质起了非常重要的作用。取少量脱氧剂于试管中,滴加足量稀盐酸的现象是______________________________________;脱氧剂的作用原理是其中的铁粉与氧气、水发生反应生成氢氧化铁,该反应的化学方程式为__________;据此判断脱氧剂对食品具有防腐保鲜作用的原因是________________(填序号)。 a.脱氧剂具有杀菌、消毒的作用 b.脱氧剂吸收水分,使食品保持干燥 c.脱氧剂吸收氧气,防止食品发生缓慢氧化 (2)洗相液中含有较多的硝酸银,通常使用铁将其置换出来,相应的化学反应方程式是 ___________________________________________________; (3)工业上主要利用一氧化碳高温还原赤铁矿(主要成分为氧化铁)来炼铁,其化学方程式为__________________________________________;用1000t 含氧化铁80%的赤铁矿可以炼出含铁96%的生铁______________t 。(结果保留1位小数) 【答案】固体部分溶解,有气体生成,溶液由无色变为浅绿色 4Fe+3O 2+ 6H 2O 4Fe(OH)3 bc Fe+ 2AgNO 3 == 2Ag+ Fe(NO 3)2 Fe 2O 3+3CO 2Fe+3CO 2 583.3 【解析】 (1). 由题中信息可知,脱氧剂的主要成分有铁,铁和稀盐酸反应生成氯化亚铁和氢气,观察到固体部分溶解,有气体生成,溶液由无色变为浅绿色 (2). 铁粉与氧气、水发生反应生成氢氧化铁,反应的化学方程式为4Fe+3O 2+ 6H 2O 高温4Fe(OH)3 (3). 脱氧剂对食品具有防腐保鲜作用的原因是脱氧剂吸收水分,使食品保持干燥、脱氧剂吸收氧气,防止食品发生缓慢氧化而变质; (4).铁的活动性比银强,能与硝酸银反应生成硝酸亚铁和银,方程式为: Fe+ 2AgNO 3 == 2Ag+ Fe(NO 3)2 (5).一氧化碳有还原性,高温下能与氧化铁反应生成铁和二氧化碳,反应方程式为 Fe 2O 3+3CO 高温2Fe+3CO 2 (6). 据质量守恒定律可知反应前后元素的质量不变,所以氧化铁中铁元素的质量等于生铁中铁的质量,设生铁的质量为x ,=100%??化学式中某原子的个数其相对原子质量化合物中元素的质量分数化合物的相对分子质量,则