một người đi xe máy đang chuyển động với vận tốc 10m/s . để ko va vào con chó, người ấy phanh xe . biết độ dài vết phanh xe là 5m. tính giá trị của gia tốc/mình cần gắp

một vận động viên bơi về phía bắc với vận tốc 1,7 m/s . nước sông chạy với vận tốc 1 m/s về phía đông . tìm độ lớn và hướng vận tốc tổng hợp của vận động viên/ mình cần gấp lắm 

cho 200ml dd sulfuric acid 1M tác dụng vừa đủ với x ml dung dịch barium chloride 1,5M 

a) tính khối lượng kết tủa thu được?

b) tính thể tích của dung dịch barium chloride đã dùng ?

c)tính nồng độ mol của các chất có trong dd sau phản ứng ?

d) cho quỳ tím vào dung dịch thu được sau phản ứng . nêu hiện tượng thấy được ở quỳ tím . giải thích

cho H=1, Cl=35,5; Ag=108, N=14 ,O=16, Ba = 137, S= 32

1.  Fe  + O₂ -->                                      21. Mg + HCl -->      

2. KClO₃ -->                                     22. Mg + H₂SO₄ --> 

3. CH₄ + O_2-->                                      23. Na + HCl -->

4. P + O₂                                           24. Fe + H₂SO₄

5. S+ O₂                                            25. Fe + HCl

6. Na + O₂                                         26. Al + HCl  

7. Mg + O₂                                        27. Al + H₂SO₄

8. Al + O₂                                          28. Zn + HCl

9. Zn + O₂                                         29. Zn + H₂SO₄

10. Cu + O₂                                       30. K + H₂O

11. C + O₂                                        31. Na + H₂O

12. KMnO₄                                                 32. Ba + H₂O

13. H₂ + O₂                                       33. Ca + H₂O

14. H₂ + CuO                                   34. CaO + H₂O

15. H₂ + Fe₂O₃                                 35. K₂O + H₂O

16. H₂ + FeO                                    36. Na₂O + H₂O

17. H₂ + Fe₃O₄                                 37. BaO + H₂O

18. H₂ + PbO                                    38. SO₃ + H₂O

19. H₂ + ZnO                                    39. P₂O₅ + H₂O

20. H₂ + HgO                                   40. CO₂ + H₂O  

Bài 2: Viết PTHH để thực hiện chuỗi biến hoá sau:

a. H₂ -->H₂O -->O₂ -->Fe₃O₄ --> Fe --> FeSO₄

b. P  P₂O₅  H₃PO₄  Ca₃(PO₄)₂

c. Ca  CaO  Ca(OH)₂  CaCO₃

Bài 3: Phân loại và gọi tên các chất sau:

Na₂CO₃, H₃PO₄, Mg(OH)₂, AgCl, Al(OH)₃, H₂SO₃, CuSO₄, NaHSO₄, H₂S, Fe(OH)₃, Ca(H₂PO₄)₂, LiOH, Mg(NO₃)₂, H₂SO₄, CrCl₃, Ba(OH)₂, HNO₃, K₂SO₃, NaNO₂, Ca₃(PO₄)₂, HCl, MgCO₃, ZnBr₂, HBr, Fe₂(SO₄)₃, Ca(HCO₃)₂, Zn(OH)₂, AlPO₄, FeCl₃, Cu(NO₃)₂.

Công thức tính số mol chất khí ở đkc (V = n.24,79)

Bài 4:

Hoà tan hết 16,8g sắt Fe trong 200g dung dịch hydrochloric acid HCl thu được muối và khí hydrogen.

a. Tính thể tích khí hydrogen sinh ra ở đktc?

b. Tính nồng độ phần trăm của dung dịch hydrochloric acid đã dùng?

Bài 5:

  Hoà tan 19,5 g kẽm bằng  dung dich hydrochloric acid

a.   Thể tích khí H₂ sinh ra (đktc)?

b.   Nếu dùng thể tích H₂ trên để khử 19,2 g iron (III) oxide thì thu được bao nhiêu gam sắt?

( Fe = 56, H = 1, Cl = 35,5; Zn = 65; O = 16)

2. The nurse told me ________to the waiting room.

A. to return B. returning C. return D. returns

3. I need ________your height.

A. measuring B. to measure C. measures D. measure

4. You should ________your hands before meals.

A. to wash B. washing C. wash D. washes

5. Were you ever ________from school last semester?

A. lately B. earlier C. absent D. presence

2. Eating too much candy is really ____________. (health)

3. Peter was _____________ last week so he didn’t take part in the competition. (sickness)

4. I had to fill in my ______________ records. (medicine)

5. My sister has an ____________________ with her customer at 7 o’clock. (appoint)

6. The nurse needs to know Tuan’s _____________. (weigh)

III. Rewrite each of the following sentences in another way so that it means almost the

same as the sentence printed before it. (1.5 pts)

1. What’s the price of your shirt?

 How much__________________________________?

3. Don’t forget to call me tonight.
 Remember _____________________________________________________________

Điểm kiểm tra 1 tiết môn Địa Lí của học sinh lớp 7C được ghi lại trong bảng sau:

2 4 3 6 7 5 5 7 4 7
6 6 9 7 6 9 6 8 7 5
7 9 7 9 8 7 8 10 6 8

a) Dấu hiệu cần quan tâm là gì ? (1đ)
Có bao nhiêu bạn tham gia làm bài kiểm tra ? (1đ)
b) Số các giá trị khác nhau của dấu hiệu ? (1đ)
c) Lập bảng tần số ? (2đ)
d) Tính tỉ lệ phần trăm số học sinh đạt điểm giỏi ? (1đ)

18. She made a cushion and a dress. The cushion was fine. But the dress________.

A. was B. isn’t C. Wasn’t D. aren’t

19. We ________Cham temples and Tri Nguyen Aquarium.

A. visited B. looked C. came D. went

II. Fill in each blank with a suitable preposition.
1. Mr. Thanh has an appointment _________4 o’clock this afternoon.
2. I received a letter __________________ my parents last week.
3. Last month we visited an old church. It’s _________the suburb _________the city

4. Mrs. Quyen is a very good doctor. She looks _________sick people very carefully.
5. Are you scared ________seeing the dentist?
6. I know how to take care ________myself.
7. Hoa’s new skirt was white ________red and yellow flower ________it.
8. Lien made a cushion ________her own room.
9. Did you speak ________Mr. Robinson ________your vacation ________Dalat?
10. Lam was tired ________the blue shirt because it didn’t fit.
III. Use the correct forms of the words
1. Jane likes to wear ____________________________ clothes. (color)
2. Mary is having a bad ________________________. (tooth)
3. Fruit juice and milk are __________________ drinks. (health)
4. Most_______________________people will recover from a cold within a week (health)
5. I have an______________________with my doctor at 7 pm. (appoint)
6. We are all __________________because we will have the final exam tomorrow. (worry)
7. Mr. Pike had lots of _______________________________today. (appoint)
8. It is very easy to stay __________________ by doing exercises regularly. (health)
9. It’s important to exercise __________________________. (regular)
10. We are very ____________________________ about the final exam. (worry)
11. What a ___________________________picture! (wonder)
12. We need a _______________________ machine to mend this shirt. (sew)
13. Water is _______________________. (color)
14. Ms. Mai cuts hair for women and men. She is a _______________( hair)
15. They want a new shirt, so they go to see the _______________________. (dress)
16. How long does it take you to do this work? It takes me_____________ two hours. (near)
17. In Nha Trang, Liz visited a lot of beautiful and _________________ places. (wonder)
18. Don’t __________________ too much about the test. It’s not difficult. (worried)
19. Some people think that _____________ clothes will make them more beautiful. (color)
20. ________________________ is very important for girls. (sew)
IV. Rewrite each of the following sentences in another way so that it means almost the
same as the sentence before it.
1. Swimming is easy.
 It is ______________________________________________________________

2. Don’t stay up late at night.
 Remember not ____________________________________________________
3. What’s the matter with you?
 What’s_________________________________________________________ ?
4. Brushing your teeth is very important.
 It’s ____________________________________________________________.
5. It’s very hard to answer this question.
 Answering _____________________________________________________.
6. Finding a house in this city is difficult.
 It is ___________________________________________________________.
7. Remember to brush your teeth after meals.
 Don’t _________________________________________________________.
8. What’s wrong with him?
 What’s________________________________________________________?
9. Staying at home at this time is safe.
 It’s___________________________________________________________.
10. Don’t forget to finish all your exercises.
 Remember_____________________________________________________.

2. It’s ________to brush your teeth every day.

A. very important B. not important C. unimportant D. less important

7. What do you do ________yourself clean and tidy?

A. keep B. keeping C. to keep D. B&;C

11. Lien looks worried because she often ________to brush her teeth.

A. forget B. forgets C. to forget D. forgetting