Học tại trường Chưa có thông tin
Đến từ Chưa có thông tin , Chưa có thông tin
Số lượng câu hỏi 3
Số lượng câu trả lời 1
Điểm GP 0
Điểm SP 0

Người theo dõi (0)

Đang theo dõi (0)


Chủ đề:

Unit 1 : My friends : Test 2

Câu hỏi:

Exercise 1: Put the verbs in brackets into the correct form:

1. If I see him , I _____ (give ) him a gift.

2. If I had a typewriter, I _____ (type) it myself.

3. If I had known that you were in hospital, I _____ (visit) you.

4. You could make better progress if you _____ (attend) class regularly.

5. If I _____ (know) his telephone number, I’d give it to you.

6. If you _____ (arrive) ten minutes earlier, you would have got a seat.

7. If he worked more slowly, he _____ (not make) so many mistakes.

8. I shouldn’t drink that wine if I _____ (be) you.

9. If I _____ (find) a cheap room, I will stay a fortnight.

10. A lot of people _____ (be) out of work if the factory closed down.

Exercise 2: Make conditional sentences:

1. Keep silent or you’ll wake the baby up. →If ……………………………………………..…..………

2. Stop talking or you won’t understand the lesson.→ If …………………………………….....….…….

3. I don’t know her number, so I don’t ring her up.→ If …………………………………….....….……..

4. I don’t know the answer, so I can’t tell you.→ If …………………………………………….………..

5. We got lost because we didn’t have a map.→ If …………………………………….……..…….……

6. Susan felt sick because she ate four cream cakes. →……………………………………………..……

7. Without this treatment, the patient would have died. →……………………………………….….…...

8. He lost his job because he was late every day. →………………………………………………...……

9. Peter is fat because he eats so many chips. →……………………………………………………...…..

10. Robert got a bad cough because he started smoking cigarettes. →………………………………..…..

Exercise 3: Use UNLESS instead of IF

EX: If you do not study hard, you will fail the exam.

Unless you study hard , you will fail the exam

1. If you do not like this one, I’ll bring you another

Unless………………………………………………

2. If she does not hurry, she’ll be late

Unless ……………………………………………….

3. If you are not careful, you’ll cut yourself

Unless ……………………………………………………

4. if you had not sneezed, he wouldn’t have known that we were there.

Unless ……………………………………………………

Exercise 4: One of the four underlined parts marked A, B, C, D in each sentence is not correct in standard English. Identify them. ( Những từ in đậm là thay cho gạch ngang! )

1. If Lucia had been here now, she would find out the truth about her uncle’s accident.

A B C D

2. If a student takes a course on Computer Science, it will take him four years doing the course.

A B C D

3. Unless it did not rain, Peter would pay us a visit.

A B C D

4. If had I known you were / in financial difficulty, I would have helped you. ( mình dùng dấu gạch để dễ phân biệt hơn!)

A B C D

5. If I had knew the time when the match started, I would have told you.

A B C D

6. If she had finished / the work, she can go / home. ( mình dùng dấu gạch để dễ phân biệt hơn!)

A B C D

7. If I had spoken more confident at the interview, they would have offered me the job.

A B C D

8. If we had had a map, we would not / be lost yesterday. ( mình dùng dấu gạch để dễ phân biệt hơn!)

A B C D

9. Had I known / Alice’s address, I would write / to her. ( mình dùng dấu gạch để dễ phân biệt hơn!)

A B C D

10. If I had realized / that the traffic lights were red, I would stop.( mình dùng dấu gạch để dễ phân biệt hơn!)

A B C D

11. If had you sent the application form to that company, you would / have been offered a job. ( mình dùng dấu gạch để dễ phân biệt hơn!)

A B C D

12. He spends money carelessly / as if he was a millionaire. ( mình dùng dấu gạch để dễ phân biệt hơn!)

A B C D

13. Unless you work harder, you will be sack because of your laziness.

A B C D

14. Unless there had been the heavy storm, the climbers will not have died.

A B C D

15. She has found that nobody can help her if she did not try her best to do it herself.

A B C D

Exercise 6: Choose the best answer for each of the following sentences.

1. _____have enough apples, she’ll make an apple pie this afternoon.

A.Should she B. If she C. Will she D. Unless she

2. If you_____to me, you wouldn’t have got so much trouble.

A. listened B. would listen C. had listened D. Would have listened

3. If you don’t know how to spell a word, you_____ look it up in the dictionary.

A. must B. will C. should D. ought

4. If the sun _____, we _____for a walk.

A. shines / will go B. shone / will go C. shone / would go D. had shone / would go

5. The campfire _____ if it _____ last night.

A. wouldn’t be cancelled / hadn’t rained B. wouldn’t have been cancelled / hadn’t rained

C. would have been cancelled / hadn’t rained D. will be cancelled / rains

6. But for our parents, we _____ successful in life.

A. will never be B. would never be C. wouldn’t have be D. would have never been

7. If I _____ my wallet at home this morning, I _____ money for lunch now.

A. leave / will have B. didn’t leave / would have

C. hadn’t left / would have D. hadn’t left / would have had

8. It is too bad, Lam isn’t here. If he _____ here, he _____ what to do.

A. were / would know B. is / will know

C. had been / would have known D. was / would know

9. If we _____ the plans carefully, we would not have had so many serious mistakes.

A. study B. had studied C. studied D. were studying

10. I will never talk to you again _____ you apologize me _____ your being rude.

A. if / for B. unless / for C. or / of D. whether / or

11. _____ if you work harder, you will be sacked.

A. Whether B. If C. However D. Unless

12. I think you should stop smoking.

A. If I am you, I will stop smoking. B. If I were you, I will stop smoking.

C. If I were you, I would stop smoking. D. If I had been you, I would stop smoking.

13. If you take the ice out of the fridge, it _____.

A. vaporizes B. melts C. heats D. disappears

14. We should do something to protect water from being polluted _____we will have nothing to drink in the future.

A. if B. whether C. or D. unless

15. Let’s knock on their door to see _____ home.

A. if they’re B. unless they’re C. whether they were D. if they were

16. Unless we _____ more snow, we can’t go skiing.

A. will have B. have C. have had D. had

17. You’ll fail the exam _____ you start revising.

A. if B. until C. when D. unless

18. Unless you wash the car, you _____ not drive it at the weekend.

A. would B. could C. have to D. may

19. If Peter _____ his car before the drive, he _____ the problem of out of petrol.

A. checked / will not get B. had checked / would not have got

C. checks / will not have got D. would be checking / will not have got

20. He stepped on the mine, and it exploded.

If he doesn’t step on the mine, it doesn’t explode. If he doesn’t step on the mine, it won’t explode. If he didn’t step on the mine, it wouldn’t explode. If he hadn’t stepped on the mine, it wouldn’t have exploded.

21. In my experiments, the liquid is cooled to 32­­­ºF. It always freezes.

If you cool the liquid to 32 degrees, it froze. If you cooled the liquid to 32 degrees, it would freeze. If you cool the liquid to 32 degrees, it will freeze. If you had cooled the liquid to 32 degrees, it would have frozen.

22. It may rain this afternoon. I hope it doesn’t because I don’t want the match to be cancelled.

A. If it rains, the match is cancelled. B. If it rains, the match will be cancelled.

C. if it rained, the match would be cancelled. D. If it had rained, the match would have been cancelled.

23. Unfortunately, I don’t know Philosophy, so I can’t answer your question.

If I know Philosophy, I can answer your question. If I know Philosophy, I will be able to answer your question. If I knew Philosophy, I would be able to answer your question. If I had known Philosophy, I would have been able to answer your question.

24. _____ there are some more ideas, we can end the meeting now.

A. If B. As if C. Unless D. In case

25. If he _____ with us now, he _____ the beauty of nature of the National Park.

A. is / can enjoy B. was / will enjoy C. has been / would enjoy D. were / could enjoy

26. If they had searched more carefully, they…the watch sooner.

A. will find B. would find C. found D. would have found

27. If I had got up early, I _____ to have breakfast now.

A. have B.I had C. would have D. would have had

28. I cannot buy a new computer _____ I save enough money.

A. if B. even if C. unless D. as if

29. Most people you meet will be polite to you _____.

A. if you are polite to them B. if you will be polite to them

C. unless you are polite to them D. if you were polite to them

30. If you do so, it _____ the matter worse.

A. makes only B. would only make C. will only make D. had only made

31. You _____ English fluently unless you practice it every day.

A. will speak B. will not speak C. can speak D. did not speak

32. Hurry up _____ you will miss the bus and be late for school.

A. if B. and C. or D. as

33. You will get a good seat if you _____ first.

A. come B. came C. have come D. will come

34. Sam will not graduate_____.

A. if he passed all the tests B. if he does not pass all the tests.

C. unless he passes all the tests D. unless he had passed all the tests.

35. If I had time, I would go with you.

A.I am free and surely go with you. B.I am too busy to go with you.

C. I will go with you because I have time. D. I am free enough to go with you.

36. If Margaret hadn’t been wearing a seat belt, she…. Injured.

A. has been B. would has been C. would be D. would have been

37. If I _____ the rain yesterday, I_____ ill.

A. had not caught / would have been B. had not caught / would have not been

C. have not caught / were not D. have not caught / would have been

38. He looked frightened as if he _____ a ghost.

A. sees B. is seeing C. has seen D. had seen

39. What _____if there _____ a serious nuclear accident.

A. will happen / was B. happens / were

C. would happen / were D. would happen / had been

Exercise 7: Put the verbs in brackets into the correct form:

1. If I (know)…………………………. that you were ill, I (go)……………………… to see you.

2. If she'd had enough money, She (buy) …………………………… a car.

3. I (buy) ……………………………………….. a car If you lend me some money.

4. I (see) …………………………… him if I (go) …………………………. to the party last night.

5. We could have gone out if the weather (not be)……………………………………… so bad.

6. If the book (not be )…………………………… expensive, I'll buy it.

7. You would be very surprised if he (return)………………………………

8. I'll go out if it (not rain)……………………………….

9. They wouldn't come to the party if you (not invite) …………………………………..them

10. What ……………………………… you (do) ……………………. if you (be) ………………….. him?

11. If that hat costs much, I (buy) ……………………………. a small one.

12. If you (drive) ……………………...more carefully, you (have) ………………………… so many accidents.

13. If I (make) …………………………….. that mistake again, my teacher (get) ……………………… angry with me.

14. If I spoke English, my job (be) …………………………….. a lot easier.

15. If he (go) ……………………………….. to London yesterday, he ( meet) ………………………………. his old friend.

16. I will lend them some money if they (ask) …………………………….. me.

17. If we had known who he was, we (invite) ………………………….. him to speak at our meeting.

18. My dog (bark) …………………………… if it (hear) ………………………….. any strange sound.

19. If I (have) ………………………….. enough money, I would buy a house.

20. They (not/let) …………………………… you in if you (come) late.

21. If you (not go) ……………………………….. away, I (send) ……………………………… for a policeman.

22. If I (be) ………………………………… in your place, I (accept) …………………… Mr. Anderson’s invitation.

23. If I (win) ……………………………. a big prize in a lottery, I’d give up my job.

24. If I (be) ……………………………….. you, I (tell) …………………………… the truth.

25. I was busy. If I (have) …………………………..free time. I (go) ……………………………. to the cinema with you.

26. Why didn’t you attend the meeting?
Oh, I did not know. If I (know)……………………… I (come) ……………………..there.

27. What ……………….we(do)……………………… if they do not come tomorrow?

28. If I had enough time now, I (write) ………………………………. to my parents.

29. It’s too bad Helen isn’t here. If she (be) ………………………….. here, she (know) …………………..what to do.

30. If I (eat) …………………………… breakfast tomorrow morning, I (get) …………………………. hungry during class.

31. If she (come) ……………………………….. late again, she (lose) ……………………………her job.

32. I (let) ……………………………. you know if I (find) ……………………………………. out what’s happening.

33. If we (live) ………………………………. in a town, life would be better.

34. I’m sure he wouldn’t mind if we (arrive) ……………………………. early.

35. We (phone) ……………………………………. you if we have time.

36. If I won the lottery, I (give) ………………………………. you half the money.

37. It (be) …………………………………….. a pity if she married Fred

38. If I’m free on Saturday, I (go) ………………………….. to the mountains.

39. She (have) …………………………….. a nervous breakdown if she goes on like this.

40. I know I (feel) better if I (stop) …………………… smoking.

41. If I (be) …………………… you, I (help) ………………………… him.

42. I (understand)…………………………………….. him if he (speak) …………………………….. more slowly.

43. He didn’t listen to the teacher. If he (listen) ………………………….. carefully, he (perform) …………………… well in the examination

44. He’s waiting for his mother to come back from Chicago. If his mother (come) …………………………. home, he (have) ……………………………………. a lot of presents.

45. He wanted to buy some Christmas presents but he couldn’t. If he (afford) …………………………….. to buy, his children (be) ……………………………. very happy to greet a new year.

46. The kitchen will look better if we (have) ………………………………….. red curtains.

47. If I knew his address, I (go) ……………………….. round and see him.

48. If you (not be) ……………………. so busy, I (show) ………………………… you how to play.

49. It (be) ………………………………… quicker if you (use) a computer.

50. If we (have) ………………………………….. some eggs, I (make) ………………………………… you a cake.

51. Bring him another if he (not/like) ……………………………….. this one.

52. She (be) …………………………. angry if she (hear) …………………………. this tomorrow.

53. Unless you are more careful, you (have) …………………………….. an accident.

54. If you (like), I (get) …………………………………. you a job in this company.

55. If grandmother (be) ……………………….. 5 years younger, she (play) ………………………… some games.

56. If he sun (stop) …………………………… shinning, there (be) ………………………………………… no light on earth.

57. If I (be) ………………………………… a millionaire, I (live) ……………………. on Mars.

Exercise 8: Choose the best answer:

If I ……….a lot of money now, I …………..a new car.

A. have /will buy B. have / would buy C. had/ will buy D. had/ would buy.

If I ……………you, I …………….do that.

A. am/ will B. were /would C. were/ will D. had been/ would.

if I were offered the job, I think I ………. it.

A. take B. will take C. would take D. would have taken.

I would be very surprised if he……………..

A. refuses B. refused C. had refused D. would refuse.

Many people would be out of work if that factory………..down.

A. closes B. had closed C. closed D. would close.

If she sold her car, she ………… much money.

A. gets b. would get c. will get d. would have got.

They would be disappointed if we…………….

a. hadn’t come b. wouldn’t come c. don’t come d. didn’t come.

Would John be angry if I ……. ……his bicycle without asking?

a. take b. took c. had taken d. would take.

She ……….terrible upset if I lost this ring.

a. will be b. would be c. were d. had been.

If someone…………in here with a gun, I would be very frightened.

a. would walk b. walks c. had walked d. walked.

What would happen if you ……………..to work tomorrow?

a. don’t go b. didn’t go c. won’t go d. wouldn’t go.

We ‘ll get wet if we ………….out.

a. go b. did go c. went d. had gone.

If I go shopping, I ………some food.

a. buy b. will buy c. would buy d. would have bought.

If I find it, I ………you.

a. will tell b. would tell c. had told d. told.

What would you do if you……………a million dollars?

a. would win b. win c. had won d. won.

They ‘d be hurt if I ……………….

a. don’t go b. didn’t go c. hadn’t gone d. wouldn’t go.

If we took the 6: 30 train, we…………too early.

a. would have arrived b. arrived c. will arrived d. would arrive.

If I had known you were in hospital, I …………to see you.

a. will go b. would go c. went d. would have gone.

If I …………., I would have said hello.

a. had seen b. see c. saw d. would see.

I…………..out if I hadn’t been so tired.

a. will go b. went c. would have gone d. would go.

If I ………..a camera, I would have taken some pictures.

a. have b. had c. would have d. had had.

You won’t pass the examination……………you study more.

a. as long as b. unless c. if d. whether.

If only I …………you wanted to invest money in business.

a. had known b. knew c. have known d. know.

If I were to leave my country , I ……………disappointed.

a. probably be b. would have been c. will be d. would be.

If he hadn’t wasted too much time, he…………….in his examination.

a. would fail b. wouldn’t fail c. wouldn’t have failed. d. won’t fail.

If I had taken that English course, I ………..much progress.

a. had made b. would have made c. made d. would make.

If I were in your place, I ……….a trip to England.

a. will make b. had made c. made. d. would make.

If I ………….. you , I’d save some of your lottery winning.

a. be b. were c. am d. be not

If the car ……….. larger, we would have bought it.

a. had been b. have been c. has been d. been

If I had enough money, I ……… abroad to improve my English.

a. will go b. should go c. would go d. should have go to

Exercise 9: Rewrite the following sentences:

1. He can’t go out because he has to study for his exam.
=> If…………………………………………………..

2. She is lazy so she can’t pass the exam.
If…………………………………………………………

3. He will pay me tonight; I will have enough money to buy a car.
=> If…………………………………………………………….

4. He smokes too much; that’s why he can’t get rid of his cough.
=> If……………………………………………………………..

5. She is very shy, so she doesn’t enjoy the party.
=> If……………………………………………………………..

6. I will get a work permit. I will stay for another month.
=> If……………………………………………………………..

7. He doesn’t take any exercises. He is so unhealthy
=> If……………………………………………………………….

8. We can’t get the ticket because I don’t have the right change.
=> If………………………………………………………………..

9. Study hard or you won’t pass the exam.
=> If…………………………………………………………………..

10. Don’t be impatient or you will make mistakes.
=> If……………………………………………………………………..

11. I didn’t eat lunch, I feel hungry now.
=> If I…………..………………………………….

12. I only come if they invite me.
=> unless……………………………………………….

13. He didn’t revise all his lessons, he failed the exam.
=> If he………………………………………………………..

14. The park is over there, only 5 minutes’ walk.
=> If you walk……………………………………………….

15. Leave me alone or I’ll call the police.

=>Unless……………………………………………………………………………………

16. If you arrive at the office earlier than I do, please turn on the air-conditioner.

=> Should……………………………………………………………………………….

17. The children don’t go to school in the snowy weather.

=> If it ………………………………………………………………………………

18. He died so young; otherwise, he would be a famous musician by now.

=>Had ………………………………………………………………………………

19. You must tell me the whole truth or I won’t help you.

=> Unless………………………………………………………………………………

20. The car breaks down so often because you don’t take good care of it.

=> Were I………………………………………………………………………………

21. He is very bad-tempered, that’s why his wife left him soon after marriage.

=> If he………………………………………………………………………………

22. Don’t tell lies to your boss or you’ll be fired at once.

=> If……………………………………………………………………………

23. She got married at such an early age: otherwise, she would be at university now.

=> Had …………………………………………………………………………. - 8 -

Exercise 10: One of the four underlined parts marked A, B, C, D in each sentence is not correct in standard English. Identify them. ( Những từ in đậm là thay cho gạch ngang )

1. If we will reduce the speed of population growth, there will be less pressure on the earth.

A B C D

2. Unless we leave a bowl of water under the sun, it will evaporate.

A B C D

3. If we continue to use fuels at the current rate, we would soon have to face a fuel crisis.

A B C D

4. If I am 10 centimeters / taller, I would play basketball. ( mình dùng dấu gạch để dễ phân biệt hơn!)

A B C D

5. If the doctors could find in the remedy, a lot of people would be saved.

A B C D

6. If she bought that house now, she ran out of money.

A B C D

7. What / you would do if you could speak French well? ( mình dùng dấu gạch để dễ phân biệt hơn!)

A B C D

8. If I had known he is not at home, I wouldn’t have gone all the way to his house.

A B C D

9. If I had known that the road were flooded, I would never have taken that way.

A B C D

10. If I were you, I will go to the dentist’s and have the tooth checked.

A B C D

Làm hộ mình với ạ!!!

Chủ đề:

Bài 28: Không khí - Sự cháy

Câu hỏi:

Câu 1: Photpho đỏ (P) được sử dụng làm chất mồi lửa ở các que diêm. Khối lượng P cần dùng để tác dụng vừa đủ với 1,12 lít khí oxi (đktc) là:
A. 1,24 gam
B. 1,55 gam
C. 0,62 gam
D. 0,93 gam
Câu 2: Để bảo quản thực phẩm, người ta không sử dụng biện pháp nào sau đây?
A. Bơm khí CO2 vào túi đựng thực phẩm
B. Dùng màng bọc thực phẩm
C. Bơm khí O2 vào túi đựng thực phẩm
D. Hút chân không
Câu 3: Phần lớn các nạn nhân thiệt mạng trong các đám cháy là do ngạt, ngộ độc khói và khí độc kèm theo trong khói. Một trong những biện pháp để thoát khỏi đám cháy là nhúng chăn hoặc khăn to vào nước choàng kín người, bịt khăn ướt vào mũi, rồi di chuyển cúi thấp người ở tư thế đi khom, hoặc bò sát mặt đất men theo đường để tìm lối ra. Cách làm này được giải thích như thế nào là đúng nhất?
A. Chất khí độc CO nhẹ hơn không khí nên cần phải cúi thấp người, vải ướt để hạ nhiệt độ.
B. Khói và khí độc nóng, nhẹ hơn không khí nên cần phải cúi thấp người, vải ướt để cản khói và hạ nhiệt độ
C. Khói và khí độc nóng, nhẹ hơn không khí nên cần phải cúi thấp người, vải ướt để hấp thụ khí độc vì khí độc tan trong nước.
D. Khí oxi nặng hơn không khí nên cần phải cúi thấp người, vải ướt để hấp thụ hết khí độc vì khí độc tan trong nước.
Câu 4: Khí axetilen (C2H2) là nhiên liệu trong đèn xì oxi - axetilen để hàn cắt kim loại do nhiệt độ ngọn lửa có thể lên tới 3000 độ C. Tính thể tích khí oxi cần để đốt cháy hoàn toàn 17,92 lít khí axetilen. Biết sản phẩm của phản ứng đốt cháy axetilen là CO2 và H2O và các khí đều đo ở điều kiện tiêu chuẩn.
A. 11,2 lít
B. 22,4 lít
C. 33,6 lít
D. 44,8 lít
Câu 5: Urê (NH2)2CO là một trong những loại phân đạm được sử dụng phổ biến nhất do có nhiều ưu điểm như hàm lượng nitơ cao, giá thành rẻ, ... Thành phần phần trăm của nguyên tố dinh dưỡng (nguyên tố N) trong phân urê là:
A. 23,33%
B. 25,54%
C. 46,67%
D. 66,67%
Câu 6: Khí CO2 thường tích tụ trong đáy giếng khơi, trên nền hang sâu. Nguyên nhân là do:
A. Khí CO2 nhẹ hơn không khí
B. Khí CO2 không tan trong không khí
C. Khí CO2 nặng hơn không khí
D. Khí CO2 không duy trì sự sống
Câu 7: Khối lượng mol của hợp chất tạo bởi Fe2(SO4)3 là
A. 418 g/mol
B. 416 g/mol
C. 400 g/mol
D. 300 g/mol
Câu 8: Cho Ca(II), PO4(III), công thức hóa học nào viết đúng?
A. CaPO4
B. Ca2PO4
C. Ca2(PO4)3
D. Ca3(PO4)2
Câu 9: Hóa trị của C trong CO2 là (biết oxi có hóa trị là II)
A. I
B. II
C. III
D. IV
Câu 10: Khi đun nóng hóa chất, cần chú ý
A. miệng ống nghiệm hướng về phía người thí nghiệm để dễ theo dõi.
B. miệng ống nghiệm hướng về phía đông người.
C. miệng ống nghiệm hướng về phía không người.
D. miệng ống nghiệm hướng về phía có người và cách xa 40 cm.
Câu 11: Đốt cháy 3,2 gam lưu huỳnh trong một bình chứa 1,12 lít khí O2 (đktc). Thể tích khi SO2 thu được là
A. 1,12 lít.
B. 4,48 lít.
C. 2,24 lít.
D. 3,36 lít.
Câu 12: Cho 3,36 lít oxi (đktc) phản ứng hoàn toàn với một kim loại hóa trị III, thu được 10,2 gam oxit. Kim loại hóa trị là
A. Fe
B. Al
C. P
D. Cr
Câu 13: Hợp chất X tạo bởi 2 nguyên tố C và H, trong đó nguyên tố H chiếm 25% về khối lượng trong hợp chất. Công thức hóa học của X là
A. C2H2.
B. C2H4.
C. CH4.
D. C2H6.
Câu 14: Đốt cháy hết hỗn hợp gồm 6,75 gam bột nhôm và 9,75 gam bột kẽm cần một lượng oxi vừa đủ được điều chế từ m gam KMnO4. Giá trị m là
A. 41,475.
B. 82,95
C. 39,5.
D. 79.
Câu 15: Ở điều kiện tiêu chuẩn 6,72 lít khí CO2 có số mol là
A. 0,1 mol.
B. 0,2 mol.
C. 0,3 mol.
D. 0,4 mol.
Câu 16: Ở điều kiện tiêu chuẩn, hỗn hợp gồm 11,2 lít H2 và 5,6 lít O2 có khối lượng là
A. 8 gam.
B. 9 gam.
C. 10 gam
D. 12 gam
Câu 17: 0,25 mol vôi sống CaO có khối lượng là
A. 10 gam
B. 5 gam
C. 14 gam
D. 28 gam
Câu 18: Trong 16 gam CuSO4 có bao nhiêu gam đồng?
A. 6,4.
B. 6,3
C. 6,2
D. 6,1
Câu 19: Cho cùng một khối lượng các kim loại là Mg, Al, Zn, Fe lần lượt vào dung dịch H2SO4 loãng, dư thì thể tích khí H2 lớn nhất thoát ra là của kim loại nào sau đây?
A. Al
B. Mg
C. Zn
D. Fe
Câu 20: Đưa tàn đóm vào bình đựng khí oxi ta thấy hiện tượng như thế nào?
A. Tàn đóm tắt.
B. Tàn đóm bùng cháy.
C. Tàn đóm bốc khói.
D. Không hiện tượng.
Câu 21: Oxi phản ứng với nhóm chất nào dưới đây?
A. C, Cl2, Na.
B. C, C2H2, Cu.
C. Na, C4H10, Au.
D. Ag, N2, Mg.
Câu 22: Chọn phát biểu đúng:
A. Oxi là chất khí tan ít trong nước và nhẹ hơn không khí.
B. Oxi là chất khí tan vô hạn trong nước và nặng hơn không khí.
C. Khí oxi dễ dàng tác dụng với được nhiều đơn chất (kim loại, phi kim) và hợp chất.
D. Ở nhiệt độ cao, khí oxi dễ dàng tác dụng với được nhiều đơn chất (kim loại, phi kim) và hợp chất
Câu 23: Quá trình nào dưới đây không làm giảm lượng oxi trong không khí?
A. Sự gỉ của các vật dụng bằng sắt.
B. Sự cháy của than, củi, ga.
C. Sự quang hợp của cây xanh.
D. Sự hô hấp của động vật.
Câu 24: Sự tác dụng của oxi với một chất gọi là
A. sự oxi hóa.
B. sự cháy.
C. sự đốt nhiên liệu.
D. sự thở.
Câu 25: Sự cháy khác với sự oxi hóa chậm là
A. có phát sáng.
B. không phát sáng.
C. có tỏa nhiệt.
D. không tỏa nhiệt.
Câu 26: Phản ứng nào dưới đây là phản ứng hoá hợp?
A. KClO3 --> 2KCl + 3O2
B. CaO + H2O --> Ca(OH)2
C. 2KMnO4 --> K2MnO4 + MnO2 + O2
D. 2Fe(OH)3 --> Fe2O3 + 3H2O
Câu 27: Dãy chất nào đều là oxit?
A. CO, NO2, MgCO3.
B. SO3, HCl, FeO.
C. CO2, SO3, FeO.
D. NO, Fe2O3, NaOH.
Câu 28: Trong phòng thí nghiệm, người ta điều chế và thu khí oxi như hình vẽ dưới đây vì oxi
A. nặng hơn không khí
B. nhẹ hơn không khí.
C. rất ít tan trong nước.
D. nhẹ hơn nước.
Câu 29: Trong các phản ứng hoá học sau, đâu là phản ứng phân huỷ?
A. 2KMnO4 --> K2MnO4 + MnO2 + O2
B. 2CO + O2 --> 2CO2
C. Na2O + H2O --> 2NaOH
D. CH4 + 2O2 --> CO2 + 2H2O
Câu 30: Không khí là một hỗn hợp khí có tỉ lệ theo thể tích của các khí lần lượt là
A. 21% N2, 78% O2, 1% các khí khác.
B. 87% N2, 21% O2, 1% các khí khác.
C. 12% N2, 88% O2, 1% các khí khác.
D. 78% N2, 21% O2, 1% các khí khác.