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Câu 15:

P2O5 + 3 H2O -> 2 H3PO4

CaO + H2O -> Ca(OH)2

Na2O + H2O -> 2 NaOH

CO không tác dụng nước

Oxit tác dụng được với nước là : 1;2;4

=> Chọn B

Câu 16:

N2O5 + H2O -> 2 HNO3

SO2 + H2O ⇌⇌ H2SO3

CuO, FeO không tác dụng nước.

=> Chọn D

31 tháng 7 2021

15B

16D

11 tháng 3 2021

Oxit axit : 

SO3 : Lưu huỳnh tri oxit

P2O5 : Đi photpho penta oxit

CO2 : Cacbon đi oxit

N2O5 : Đi nitơ penta oxit

Oxit ba zơ

ZnO : Kẽm oxit

Fe2O3 : Sắt ( III) oxit

CuO : Đồng (II) oxit

CaO : Canxi oxit

Na2O : Natri oxit

MgO : Magie oxit

11 tháng 3 2021

Oxit axit : 

- SO3 : lưu huỳnh trioxit 

- P2O5 : diphotpho pentaoxit 

- CO2 : cacbon dioxit 

- N2O5 : dinito pentaoxit 

Oxit bazo : 

- ZnO : kẽm oxit 

- Fe2O3 : Sắt (III) oxit 

- CuO : Đồng (II) oxit 

- CaO : Canxi oxit 

- Na2O : Natri oxit 

- MgO : Magie oxit 

31 tháng 7 2021

9. B

10. A

23 tháng 9 2021

a) 

CO2+H2O->H2CO3

SO2+H2O->H2SO3

K2O+H2O->2KOH

P2O5+H2O->2H3PO4

b)

MgO+H2sO4->MgSO4+H2O

K2O+H2SO4->K2SO4+H2O

Fe2O3+3H2SO4->Fe2(SO4)3+3H2O

c)CO2+2NaOH->Na2CO3+H2O

SO2+2NaOH->Na2SO3+H2O

P2O5+6NaOH->2Na3PO4+3H2O

22 tháng 9 2021

Tác dụng với nước : CO2 , SO2 , K2O , P2O5

Pt : \(CO_2+H_2O⇌H_2CO_3\)

      \(SO_2+H_2O\rightarrow H_2SO_3\)

      \(K_2O+H_2O\rightarrow2KOH\)

      \(P_2O_5+3H_2O\rightarrow2H_3PO_4\)

Tác dụng với axit sunfuric : MgO , K2O , Fe2O3

Pt : \(MgO+H_2SO_4\rightarrow MgSO_4+H_2O\)

       \(K_2O+H_2SO_4\rightarrow K_2SO_4+H_2O\)

       \(Fe_2O_3+3H_2SO_4\rightarrow Fe_2\left(SO_4\right)_3+3H_2\)

Tác dụng với natri hidroxit : CO2 , SO2 , P2O5

Pt : \(CO_2+2NaOH\rightarrow Na_2CO_3+H_2O\)

       \(SO_2+2NaOH\rightarrow Na_2SO_3+H_2O\)

       \(P_2O_5+6NaOH\rightarrow2Na_3PO_4+3H_2O\)

 Chúc bạn học tốt

28 tháng 7 2021

Câu 1 : 

Trong $P_2O_5  : \%O = \dfrac{16.5}{31.2 + 16.5}.100\% = 56,34\%$

Trong $CaO : \%O = \dfrac{16}{40+16} .100\% = 28,57\%$

Trong $CO : \%O = \dfrac{16}{12 + 16}.100\% = 57,14\%$
Trong $Na_2O : \%O = \dfrac{16}{23.2 + 16}.100\% = 25,81\%$

Câu 2:

nH2=0,15(mol)

nFe2O3=0,1(mol)

PTHH: 3 H2 + Fe2O3 -to-> 2 Fe + 3 H2O

Ta có: 0,15/3 < 0,1/1

=> Fe2O3 dư, H2 hết, tính theo nFe2O3

nFe=2/3. nH2= 2/3. 0,15=0,1(mol) -> mFe=0,1.56=5,6(g)

nFe2O3(dư)= 0,1 - 1/3 . 0,15=0,05(g) -> mFe2O3=0,05.160=8(g)

 

Câu 27:

mdd= 160 : (100% - 20%)= 200(g)

=> mđường= 200-160=40(g)

=> Chọn B

Câu 29:

nKOH=0,6.4=2,4(mol)

=> Chọn B

Câu 25:

mdd=(mct.100%)/C%= (4.100)/10=40(g)

=> mH2O=mdd - mct= 40 - 4 =36(g)

=> Chọn C

Câu 26:

mdd=(mct.100%)/C%= (30.100)/20= 150(g)

=> Chọn A

Câu 21: _TH_ A lot of people get Covid-19 in China.____________ trying their best, the doctors can’t rescue all of the patients.A. Despite of B. However C. Because D. In spite ofCâu 22: _TH_ ___________ is a film in which strange and frightening things happen.A. Animation B. Action C. Horror D. ComedyChoose the letter A, B, C or D to indicate the most suitable response to complete each of the following exchanges:Câu 23: _TH_ An: “______ “A spy called 007” at Hoa Phong cinema this weekend?”Ha:...
Đọc tiếp

Câu 21: _TH_ A lot of people get Covid-19 in China.____________ trying their best, the doctors can’t rescue all of the patients.

A. Despite of B. However C. Because D. In spite of

Câu 22: _TH_ ___________ is a film in which strange and frightening things happen.

A. Animation B. Action C. Horror D. Comedy

Choose the letter A, B, C or D to indicate the most suitable response to complete each of the following exchanges:

Câu 23: _TH_ An: “______ “A spy called 007” at Hoa Phong cinema this weekend?”

Ha: “Good idea”

A. How about seeing B. Do you like seeing

C. Should you see D. Do you want to see

Câu 24: _TH_ Thomas: “Would you like to come to my house to watch Cowboy film tonight?”

Peter: “__________”

A. Yes, I do B. No, I don’t

C. I’m busy D. That would be nice.

Read the following passage and choose the letter A, B, C or D to indicate the correct word or phrase that best fits each of the numbered blanks:

Brazil’s most popular and festive holiday is Carnival. In fact, many people (25) _______ Carnival one of the world’s biggest celebrations. Each spring, on the Saturday before Ash Wednesday, the streets of Brazil’s (26) ________ city, Rio de Janeiro, come alive with parties, festivals and glamorous dances.

The Samba School Parade is the highlight of the (27) ________ event. About 3000 performers, in colourful costumes embellished with feathers, beads and thousands of sequin dance down the parade route into the Sambadrome - a dance stadium (28) ________ for the event. Judges award a prize to the most spectacular group of dancers.

Câu 25: _TH_

A. believe B. regard C. consider D. hope

Câu 26: _TH_

A. the largest B. largest C. larger D. most large

Câu 27: _TH_

A. four days B. four-day C. fouth day D. four-days

Câu 28: _TH_

A. built B. build C. to build D. building

Read the following passage and circle the letter A, B, C, or D to indicate the correct answer to each of the following questions.

My favorite movie is “Sherlock Holmes”. This is a movie I watched recently in cinema. It was a very thrilling journey through time. The film was based on a novel, with the same name. Except the great story, the actors were great. They really make you think it is happening. The main character wasn’t like the one in novel, it was the complete opposite, his assistant Dr. Watson. Who is very fat in the novel, isn’t showed like that. He is Sherlock’s conscience, very handsome, younger man, just like Holmes. In the film, he is trying to prove that magic doesn’t exist and that all that happened wasn’t because of a bad magician, and he did it. The whole movie is exciting and I didn’t want it to end. I really liked the movie and I could watch again and again… I think that’s what makes a great movie, when it’s every time thrilling as the first time you saw it.

Câu 29: _VD_ What was the film based on?

A. It was based on a novel B. It was based on a magazine
C. It was based on a book D. It was based on a newspaper

Câu 30: _VD_ Is the character in the film similar or different from the character in the novel?

A. It is quite similar B. It is different

C. It is a bit different D. It is similar

Câu 31: _VD_ __________ are mentioned as two main characters in the passage.

A. Sherlock Holmes and Watson B. Sherlock Holmes and writer

C. Sherlock Holmes and reader D. Sherlock Holmes and director

Câu 32: _VD_ What does the sentence “I didn’t want it to end” in the passage mean?

A. The writer is bored with this film

B. The writer is interested in this film

C. The writer wants the film to be longer

D. The writer has long free time to watch this film

Choose the letter A, B, C or D to indicate the most meaningful sentence made questions for underlined from the given words.

Câu 33: _VD_ Mai does her homework twice a day.

A. How long does Mai do her homework?

B. How often does Mai do her homework?

C. How far does Mai do her homework?

D. How many does Mai do her homework?

Câu 34: _VD_ Yesterday, I went to Hung King Festival with my friends.

A. When did you go with your friends yesterday?

B. Where did you go to your friends yesterday?

C. When did you went with your friends yesterday?

D. Where did you go with your friends yesterday?

Câu 35: _VD_ I felt sick after eating that food.

A. What do you do after eating that food?

B. How do you do after eating that food?

C. How do you feel after eating that food?

D. Why do you feel after eating that food?

Câu 36: _VD_ It took Dr. Linh ten minutes to fill Ba’s tooth.

A. What time did Dr. Linh fill Van’s tooth?

B. How long did it take Dr. Linh to fill Ba’s tooth?

C. How many time did it take Dr. Linh to fill Ba’s teeth?

D. How much time did Dr. Linh take to fill Ba’s teeth?

Choose the letter A, B, C or D to indicate the sentence that is closest in meaning to the original one.

Câu 37: _VD_ Miss Jenny was tired, but she watched documentary last night.

A. Despite Miss Jenny was tired, she watched documentary last night.

B. Although Miss Jenny was tired, she watched documentary last night.

C. In spite of Miss Jenny was tired, she watched documentary last night.

D. Although being tired, she watched documentary last night.

Câu 38: _VD_ Do you enjoy watching action movie or romantic movie?

A. Are you interested in watch action movie or romantic movie?

B. Are you interested in watching action movie and romantic movie?

C. Are you interested in to watching action movie or romantic movie?

D. Are you interested in watching action movie or romantic movie?

Câu 39: _VD_ What’s the distance between New York city and Boston?

A. How far is it from New York city to Boston?

B. How far is it from New York city and Boston?

C. How far is it to New York city to Boston?

D. How far is it to New York city from Boston?

Câu 40: _VD_ My uncle drove carelessly some years ago, but now he doesn’t.

2
10 tháng 3 2022

e tách ra nhé .-.

10 tháng 3 2022

mk sẽ giúp bạn trong một thời gian nữa

mk hứa đấy

kiên nhẫn lên nhé

28 tháng 3 2019

Lấy mẫu thử và đánh dấu mẫu thử

Cho các mẫu thử vào nước

Mẫu thử tan trong nước: Na2O; P2O5.

Na2O + H2O => 2 NaOH

P2O5 + 3H2O => 2H3PO4

Mẫu thử không tan trong nước là MgO

Cho quỳ tím vào các mẫu thử

Mẫu thử làm quỳ tím hóa đỏ, chất ban đầu là P2O5

Mẫu thử làm quỳ tím hóa xanh, chất ban đầu là Na2O

28 tháng 3 2019

Trích các mẫu thử ra từng ống nghiệm

Cho thêm nước vào và khuấy lên, sau đó cho quỳ tím vào

+ Na2O: quỳ tím hóa xanh

\(PTHH:Na_2O+H_2O\rightarrow2NaOH\)

+ P2O5: quỳ tím hóa đỏ

\(PTHH:P_2O_5+3H_2O\rightarrow2H_3PO_4\)

+ MgO: không có hiện tượng xảy ra vì MgO là oxit không tan trong nước