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NP
1 tháng 1 2019
Đề 1
Câu 3
a, Al2O3 + 2NaOH ---> 2NaAlO2(B1) + H2O
Al + NaOH + H2O ----> NaAlO2(B1) + 1,5H2(C1)
A1 gồm : Fe và Fe3O4
Al2O3 + 3H2 ---> 2Al(A2) + 3H2O
Fe3O4 + 4H2 ----> 3Fe(A2) + 4H2O
Fe và Al ko td dc với H2SO4 đặc nguội ( bị thụ động ) --> B2 là dd H2SO4
H2SO4 + BaCl2 ---> BaSO4 (B3) + 2HCl
b,
Cho vào các dd thì đầu tiên đều xảy ra hiện tượng Na tan trong dd có sủi bọt khí : Na + H2O ---> NaOH + 1/2 H2
- NH4Cl : có khí mùi khai (NH3) bay ra
NH4Cl + NaOH ---> NaCl + NH3 + H2O
-FeCl3 : dd nhạt màu dần, xuất hiện kết tủa màu nâu đỏ
FeCl3 + 3NaOH ---> Fe(OH)3 + 3NaCl
-Ba(HCO3)2 : xuất hiện kết tủa trắng
Ba(HCO3)2 + 2NaOH ---> BaCO3 + Na2CO3 + 2H2O
-CusO4 : xuất hiện kết tủa xanh
CuSO4 + 2NaOH ---> Na2SO4 + Cu(OH)2
Câu4
a, Trích mẫu thử ,,,
-Cho dd HCl vào từng ống nghiệm
+ Nếu ống no chất răn tan, có khí bay ra thì chứa K2CO3 hoặc hh KCl và K2CO3(1)
K2CO3 + 2HCl ---> 2KCl + CO2 + H2O
+ chất rắn tan, ko ht gì : KCl
-Cho dd AgNO3 vào 2 ống no nhóm 1 nếu xuất hiện kt trắng -> chứa hh KCl và K2CO3 . ko ht thì chứa K2CO3
AgNO3 + KCl ---> AgCl + KNO3
bn chup ro de ra ko thay ro lem mấy câu còn lại
11 tháng 3 2018
Em vào link dưới để tham khảo nha!
https://hoc24.vn/topic/so-do-tu-duy.11388/
Nếu ko xem được thì em vào link khóa học dưới đây. trong khóa học cô đã có đầy đủ sơ đồ tư duy của các bài lớp 6.
https://hoc24.vn/bg/sinhhoc_lop6/
11 tháng 3 2018
nhưng cô ơi em chỉ cần mỗi bài 46 thôi ạ
cô giúp em với
VB
22 tháng 12 2018
2x(X-1)- 2x(X+1) = 7
=> 2x(X-1-X+1) =7
<=> 2xX=7
=> x = 7/2 = 3.5
E
3 tháng 11 2018
7292018 = (93)2018 = 96054 < 106054
Ta có: 106054 có 6055 chữ số (1 chữ số 1 và 6054 chữ số 0)
=> 7292018 có ít hơn 6055 chữ số
4 tháng 2 2021
I-Choose the best option to complete each of the following sentences.
1. They shouted and looked ________at me when I broke the vase.
A. angry B. angrier C. angrily D. anger
2. He is tired, ________he stayed up late watching TV.
A. so B. because C. but D. and
3. We are talking about the preservation of ________resources.
A. natural B. naturally C. nature D. naturalize
4. Is he really ________that you can’t come there?
A. disappoint B. disappointed C. disappointing D. to disappointing
5. It is our policy to ________forest and increase forestation.
A. protect B. protecting C. to protect D. protected
6. I suggest ________to the movies.
A. go B. to go C. going D. went
7. They made their living by ________fish in the ocean every day.
A. catch B. catching C. to catch D. caught
8. I will be ________if she manages to sell that motorbike at a high price.
A. surprise B. surprised C. suprising D. to surprise
9. If you know where she lives, please let me ________.
A. know B. knew C. known D. to know
10. If you live in this small town, you ________earn much money.
A. aren’t B. couldn’t C. can’t D. didn’t
11. Unless you understand, I ________explain it again to you.
A. am B. was C. will D. would
12. If he ________a student, he will get a discount.
A. is B. was C. were D. will be
13. Because plastic bags are very hard to ________, they will cause pollution.
A. dissolve B. wrap C. tear D. collect
14. These materials can be ________into other packaging products.
A. reused B. reduced C. removed D. recycled
15. If people ________public transport, there will be less pollution.
A. use B. will use C. can use D. used
16. Minh’s English is excellent. He speaks ________.
A. perfectly English B. English perfectly C. in perfect English D. English perfect
17. If you go ________doing that, you’ll end ________ in serious trouble.
A. up/ with B. on/ up C. off/ with D. out/ up
18. Crops are sprayed with ________to kill insects.
A. fertilizer B. manune C. dung D. pesticide
19. What about ________used paper, bottles, and cans every day?
A. collect B. collecting C. to collect D. to collecting
20. If the sea water continue to be polluted, many fish species ________extinct.
A. became B. will become C. would become D. become
K
4 tháng 2 2021
I-Choose the best option to complete each of the following sentences.
1. They shouted and looked ________at me when I broke the vase.
A. angry B. angrier C. angrily D. anger
2. He is tired, ________he stayed up late watching TV.
A. so B. because C. but D. and
3. We are talking about the preservation of ________resources.
A. natural B. naturally C. nature D. naturalize
4. Is he really ________that you can’t come there?
A. disappoint B. disappointed C. disappointing D. to disappointing
5. It is our policy to ________forest and increase forestation.
A. protect B. protecting C. to protect D. protected
6. I suggest ________to the movies.
A. go B. to go C. going D. went
7. They made their living by ________fish in the ocean every day.
A. catch B. catching C. to catch D. caught
8. I will be ________if she manages to sell that motorbike at a high price.
A. surprise B. surprised C. suprising D. to surprise
9. If you know where she lives, please let me ________.
A. know B. knew C. known D. to know
10. If you live in this small town, you ________earn much money.
A. aren’t B. couldn’t C. can’t D. didn’t
11. Unless you understand, I ________explain it again to you.
A. am B. was C. will D. would
12. If he ________a student, he will get a discount.
A. is B. was C. were D. will be
13. Because plastic bags are very hard to ________, they will cause pollution.
A. dissolve B. wrap C. tear D. collect
14. These materials can be ________into other packaging products.
A. reused B. reduced C. removed D. recycled
15. If people ________public transport, there will be less pollution.
A. use B. will use C. can use D. used
16. Minh’s English is excellent. He speaks ________.
A. perfectly English B. English perfectly C. in perfect English D. English perfect
17. If you go ________doing that, you’ll end ________ in serious trouble.
A. up/ with B. on/ up C. off/ with D. out/ up
18. Crops are sprayed with ________to kill insects.
A. fertilizer B. manune C. dung D. pesticide
19. What about ________used paper, bottles, and cans every day?
A. collect B. collecting C. to collect D. to collecting
20. If the sea water continue to be polluted, many fish species ________extinct.
A. became B. will become C. would become D. become
what ????