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9 tháng 11 2021

1scvbandtqtfwwđ

9 tháng 11 2021
a Cao + h2o ----> ca(oh)2 b 4P + 5o2 ----t°----> 2p2o5 c 2KClO3-----t°---> 2Lcl + 3o2 d Zn + 2hcl ----> zncl2 + h2 e CaCO3 + H2SO4----> CaSO4 + CO2 + H2O
14 tháng 11 2021

a) Canxi oxit + Nước −−−> Canxi hidroxit

b) Photpho + Oxi −−to−> Điphotpho pentaoxit 

c) Kali clorat −−to−> Kali clorua + Oxi

d) Kẽm + Axit clohidric −−−−−−> Kẽm clorua + Hidro

e) Canxi cacbonat + Axit sunfuric −−−−−−> Canxi sunfat + Cacbon đioxit + Nước

8 tháng 11 2021
Điều chế CaO: CaCO3--t°-->CaO + CO2 Điều chế SO2 S + O2-- t°--> SO2 Điều chế H2SO4: SO3 + H2O ---> H2SO4 Điều chế naoh: 2Nacl +2h2o __dpdddcmn__ 2naoh + h2 + cl2
8 tháng 11 2021

a) Gọi công thức của X là CxHyOz

Ta có: mC = (13,44 . 12)/22,4 = 7,2 (gam); mH = 9.2/18 = 1 (gam)

MO = 16,2 – 7,2 = 8 (gam)

=>x : y : z = 7,2/12 : 1/1 : 8/16 = 0,6 : 1 : 0,5 = 6 : 10 : 5

Vậy CTPT của X là (C6H10O5), X là polisaccarit.

b) (C6H10O5)n+ nH2O→H+ nC6H12O6.

1 mol n mol

16,2/162n mol a mol

=>a = 0,1 mol

C5H11O5CH=O + 2AgNO3 + 3NH3 + H2O → C5H11O5COONH4 + 2Ag ↓ + 2NH4NO3.

Theo phương trình, ta có: nAg = 0,2 mol

Vì hiệu suất phản ứng bằng 80% =>mAg = (0,2 . 108.80)/100 = 17,28 (gam)

8 tháng 11 2021

TL ;

Ai cop mạng mình cũng k hết

HT

1. ………….is only a short walk from my house to the cinema. A. There B. It C. This D. That 2. There are far more opportunities for young people than there …… A. was   B use  C. used  D. used to be 3. There is nothing very ……….to do in that small town. A. interest B. interested C. interesting D. interestingly 4. Cyclists must …………………….for pedestrians when they are cycling along the country lane.A. see off B. look out C. avoid D. observe 5. In Britain there is an...
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1. ………….is only a short walk from my house to the cinema. A. There B. It C. This D. That

 

2. There are far more opportunities for young people than there …… A. was   B use  C. used  D. used to be

 

3. There is nothing very ……….to do in that small town. A. interest B. interested C. interesting D. interestingly

 

4. Cyclists must …………………….for pedestrians when they are cycling along the country lane.

A. see off B. look out C. avoid D. observe

 

5. In Britain there is an enormous market for …….pizzas. A. freeze  B. freezing C. froze D. frozen

 

6. The new film has good audience figures …………………….poor reviews in the press.

A. despite B. in spite C. although D. nevertheless

 

7. Sales are poor now. There may, .….,be an increase before Christmas. A. however B. although C. even if  D. but

 

8. – “…………………….did you first meet Kaye, Khanh?”    - “In Da Nang last summer.”

A. Where B. Why C. What D. How

 

9. He became …………………….when a journalist asked him questions about his private life.

A. embarrass B. embarrassed C. embarrassing D. embarrassingly

 

10. …………………….do the buses run? – Every ten minutes.

A. How B. How many C. How often D. What time

 

III. Who are these notices for? Mark A, B, or C for your answers.

1. Roadwork ahead. A. Drivers B. Workers C. Customers

 

2. First class ticket holders only. A. People at a museum   B. People in a cinema  C. People on a train

 

3. Please fasten your seatbelt. A. Students B. Airline passengers    C. People in a theatre

 

4. Please do not talk to the driver A. In your car B. In a shop C. On a bus

 

5. Tyres changed here A. At a garage B. At the cinema C. At a supermarket

 

IV. Use the correct form of the words in brackets to complete the sentences.

 

1. The plane’s (depart) …………………….was delayed because of (mechanic) ……………………. difficulties. The passengers (tell) …………………….that they would have to wait for three hours.

 

2. What a (love) …………………….painting. Your daughter must be very (art) ………………., Mrs. Green.

 

3. Harvest festival was the occasion for the (express) ……………….of the community’s beliefs and values.

 

4. The traffic in some cities now is so (chaos) …………….that it is difficult to see any (solve) …………….

 

5. Madonna’s (perform) …………………….in the film is praised by many (critic) …………………….

 

…………………………………………………………………………………………

0
1. We/ used/ school/ on/ foot.……………………………………………………………………………………………………….2. about / 30km/ my town/ Ha Long Bay/.……………………………………………………………………………………………………….3. My family/ used/ go / holiday / seaside / summer/.……………………………………………………………………………………………………….4. How/ long / it /...
Đọc tiếp

1. We/ used/ school/ on/ foot.
……………………………………………………………………………………………………….


2. about / 30km/ my town/ Ha Long Bay/.
……………………………………………………………………………………………………….


3. My family/ used/ go / holiday / seaside / summer/.
……………………………………………………………………………………………………….


4. How/ long / it / take/ you/ Ha Noi / Sa Pa/?
……………………………………………………………………………………………………….


5. There / used / be / a factory / town centre / but/ it / move/ the/ suburbs/.
……………………………………………………………………………………………………….


6.  You/ must / learn / about / road safety/ before/ riding/ your/ bike/ road/.
…………………………………………………………………………………………

 

2
8 tháng 11 2021

1. We used to go to school on foot.

2. It's about 30 km from my town to a Long Bay.

3. My family used to go on holiday at the seaside in the summer.

4. How long does it take you to go from Hanoi to Sapa.

5. There used to be a factory in the town centre but it had been moved to the suburbs.

6. You must learn about road safety before riding your bike on the road.

8 tháng 11 2021

1. We used to go to school on foot.

2. It's about 30 km from my town to Hạ Long Bay.

3. My family used to go on holiday to the seaside in the summer.

4. How long does it take you to go from Hanoi to Sapa.

5. There used to be a factory in the town centre but it had been moved to the suburbs.

6. You must learn about road safety before riding your bike on the road.

1. We must be quick. There’s …………time left.   A. little B. few C. much D. more 2. He made the soup by mixing ………… meat with some rice.  A. little B. few   C. a little D. a few 3. Luckily, I ………few mistakes in my last exam. A. make B. made  C. have made  D. am making 4. You look very …………. I’m sure you play sports regularly. A. thin B. fat   C. fit D. well 5. Hamlet is an example of a ……. It has an unhappy ending. A. tragedy B. character C. comedy  D....
Đọc tiếp

1. We must be quick. There’s …………time left.   A. little B. few C. much D. more

 

2. He made the soup by mixing ………… meat with some rice.  A. little B. few   C. a little D. a few

 

3. Luckily, I ………few mistakes in my last exam. A. make B. made  C. have made  D. am making

 

4. You look very …………. I’m sure you play sports regularly. A. thin B. fat   C. fit D. well

 

5. Hamlet is an example of a ……. It has an unhappy ending. A. tragedy B. character C. comedy  D. play

 

6. I …………such nice and enthusiastic volunteers before.

 

A. never meet B. have never met C. never met D. will never meet

 

7. I want to pass the test, …………I’m studying hard.  A. but B. because C. so D. although

 

8. Paul is similar to his brother in their interest ………horse riding. A. to B. with    C. for D. in

 

9. I am not ready yet and …………A. she is too B. she is not C. so is she D. she isn’t either

 

10. They play was very long, but there were two……… A. intervals  B. rests  C. interruptions D. gaps

……………………………………………………………………………………….

6
8 tháng 11 2021

1. We must be quick. There’s …………time left.   A. little B. few C. much D. more

2. He made the soup by mixing ………… meat with some rice.  A. little B. few   C. a little D. a few

3. Luckily, I ………few mistakes in my last exam. A. make B. made  C. have made  D. am making

4. You look very …………. I’m sure you play sports regularly. A. thin B. fat   C. fit D. well

5. Hamlet is an example of a ……. It has an unhappy ending. A. tragedy B. character C. comedy  D. play

6. I …………such nice and enthusias volunteers before.

A. never meet B. have never met C. never met D. will never meet

7. I want to pass the test, …………I’m studying hard.  A. but B. because C. so D. although

8. Paul is similar to his brother in their interest ………horse riding. A. to B. with    C. for D. in

9. I am not ready yet and …………A. she is too B. she is not C. so is she D. she isn’t either

10. They play was very long, but there were two……… A. intervals  B. rests  C. interruptions D. gaps

……………………………………………………………………………………….

8 tháng 11 2021

1 A

2 C

3 B

4 C

5 A

6 B

7 C

8 D

9 C

10 A

Sandwiches are common in many countries. But (1) ……                 ……did this strange name come from? The Earl of Sandwich (1718 – 1792) was an Englishman. He liked (2) …                        ………cards. One night he played for hours and got very hungry. (3) ……                    …… he didn’t want to stop his card games. He asked for some roasts meat (4) …                            ……… two pieces of bread. (People bake roast meat in the oven or a stove). He...
Đọc tiếp

Sandwiches are common in many countries. But (1) ……                 ……did this strange name come from? The Earl of Sandwich (1718 – 1792) was an Englishman. He liked (2) …                        ………cards. One night he played for hours and got very hungry. (3) ……                    …… he didn’t want to stop his card games. He asked for some roasts meat (4) …                            ……… two pieces of bread. (People bake roast meat in the oven or a stove). He ate the food (5) ……                                       …… he played cards. People gave his name (6) ……                                           …… this new kind of food.

Pizza is (7) ……                                            ……international food. A baker probably (8) ………                            …the pizza in Naples, Italy. It was about the same time (9) ……                                                               …… the first sandwich. “Pizza” means “pie” in Italian. People (10) ……                                     …… the name “pizza pie” for a long time. Now it is just “pizza”.

1.                            A. what                                  B. when                              C. where                                     D. how

 

2. A. play                                                       B. played                                              C. plays                                D. playing

 

3. A. So                                                     B. Moreover                                                         C. But                              D. Because

 

4. A. for                               B. between                        C. on                         D. among

 

5. A. while                                           B. until                           C. after                                 D. before

 

6. A. to                                B. for                    C. from                                      D. with

 

7. A. other                       B. another                              C. others                               D. the other

 

8. A. did                                B. discovered                           C. invented                         D. found

 

9. A. than                            B. as                                                          C. like                                                D. from

 

10. A. was used                    B. have used                                               C. use                              D. used

1
8 tháng 11 2021

1.C

2.D

3.C

4.D

5.A

6.B

7.D

8.C

9.B

10.B

1. People invented the wheel thousands of years ago. __________________________________________ 2. Are they building a statue of Chu Van An? .                                                                                                                  3. Do four busy streets surround the Temple of Literature?                                                                                                       .4. They will not provide pencils at the test, so please bring your own.         ...
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1. People invented the wheel thousands of years ago. __________________________________________

 

2. Are they building a statue of Chu Van An? .                                                                                                                 

 

3. Do four busy streets surround the Temple of Literature?                                                                                                       

.

4. They will not provide pencils at the test, so please bring your own.                                                                                             

.

5. Mr. Binh hasn’t taught us since the last semester.                                                                                                                   

.

6. A student teacher is doing that experiment. .                                                                                                                                   

 

7. Did you buy this dictionary two weeks ago?                                                                                                                          

.

8. Alan’s knowledge about science and technology doesn’t impress me.                                                                                              

.

9. They are going to build a new school here next year.                                                                                                                             

.

10. I have used this computer for two years.                                                                                                                         

1
8 tháng 11 2021

1. The wheel was invented thousand of years ago.

2. Are the statue of Chu Van An being built (by them)?

3. Is Temple of Literature surrounded by four busy streets?

4. Pencils are not provided at the test, so please bring your own.

5.We hasn't been taught by Mr. Binh since the last semester.

6. That experiment is being done by a student teacher.

7. Was this dictionary bought (by you) two weeks ago?

8. I'm not impressed with Alan's knowledge about science and technology.

9. A new school is going to be built here next year (by them).

10. This computer have been used for two years (by me).

Kali có nguyên tử khối là 39 và hóa trị là I. 

8 tháng 11 2021

nguyên tử khối là 39

hóa trị I