Trong công nghiệp axit hno3 được điều chế từ khí nh3. vậy 1 mét khối khí nh3 (đktc) điều chế được khối lượng hno3 là (biết hiệu suất cả quá trình là 97%)

Cho 9,2 gam hỗn hợp X gồm Cu và Fe tác dụng với HNO3 đặc nóng, dư thu được 16,1 gam khí NO2 là sản phảm khử duy nhất của Nito +5.

a) Xác dujnhd thành phần phần trăm khối lượng mỗi kim loại trong hỗn hợp X>

b) Cho 9,2 gm hỗn hợp X tác dụng với dung dịch HNO3 loãng dư thu được V lít hỗn hợp khí gồm NO và N2O (có tỉ lệ mol tương ứng là 16:1). Tính V

Giúp mình câu b với cảm ơn nhiều nha

Bài tập 6: Giải các bất phương trình sau:

|x-2|+3x+1<4

|x-2|+x²+3x+1<6

|2x-1|+|3x+2|>6

|2x-1|+|x²-3x+2|>3

|3x+2|+x²-3x+1<0

|x²-x+2|+x²-3x+1<

|2x²-x+1|+|x²+3x+2|≤6

35,95 gam hh gồm MgCl₂ và muối clorua của kim loại M hoá trị II được hoà tan vào nước thành 200 gam dd X. 200 gam dd X tác dụng vừa đủ với 200 ml dd Na₂CO₃ 1M thu được m gam kết tủa và dd Y.

a) Tính m.

b) Tìm kim loại M biết M là một trong số các kim loại sau: Fe, Be, Zn, Ca, Sr, Ba.

Câu 9: Cho 13,05 gam MnO₂ tác dụng vừa đủ với m gam dd HCl 36,5%, đun nóng.

a) Tính thể tích khí thu được (ở đktc). (Giả sử hiệu suất phản ứng là 100%).

b) Tính m gam và nồng độ phần trăm chất có trong dung dịch thu được.

c) Để trung hoà m gam dd HCl trên cần dùng V (l) dd NaOH 8% (khối lượng riêng 1,07 gam/ml). Tính V.

mình hỏi phần 2 ý b và câu c

Câu 7: Chia 500 ml dung dịch X gồm FeCl₃ và MgCl₂ thành hai phần bằng nhau. Phần 1 tác dụng vừa đủ với 0,09 mol AgNO₃. Phần 2 tác dụng với dd NaOH dư, lọc kết tủa rồi nung nóng, thu được 2,0 gam chất rắn. Tính nồng độ mol/lít các chất trong dd X, biết các phản ứng xảy ra hoàn toàn.

Câu 8: Điện phân 200 gam dd NaCl 23,4 % có màng ngăn xốp. Sau một thời gian thu được dd A và 2,24 lít H₂ (ở đktc).

a) Tính thể tích khí Cl₂ thu được ở đktc.

b) Tính nồng độ phần trăm chất có trong dd A.

c) Cho lượng Cl₂ trên tác dụng với lượng dư kim loại M hoá trị II thu được 13,5 (g) muối. Tìm kim loại M.

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

           The handling and delivery of mail has always been a serious business, underpinned by the trust of the public in requiring timeliness, safety, and confidentiality. After early beginnings using horseback and stagecoach, and although cars and trucks later replaced stagecoaches and wagons, the Railway Mail Service still stands as one of America’s most resourceful and exciting postal innovations. This service began in 1832, but grew slowly until the Civil War. Then from 1862, by sorting the mail on board moving trains, the Post Office Department was able to decentralize its operations as railroads began to crisscross the nation on a regular basis, and speed up mail delivery. This service lasted until 1974. During peak decades of service, railway mail clerks handled 93% of all non-local mail and by 1905 the service had over 12,000 employees.

Railway Post Office trains used a system of mail cranes to exchange mail at stations without stopping. As a train approached the crane, a clerk prepared the catcher arm which would then snatch the incoming mailbag in the blink of an eye. The clerk then booted out the outgoing mailbag. Experienced clerks were considered the elite of the Postal Service’s employees, and spoke with pride of making the switch at night with nothing but the curves and feel of the track to warn them of an upcoming catch. They also worked under the greatest pressure and their jobs were considered to be exhausting and dangerous. In addition to regular demands of their jobs they could find themselves the victims of train wrecks and robberies.

          As successful as it was, “mail-on-the-fly” still had its share of glitches. If they hoisted the train’s catcher arm too soon, they risked hitting switch targets, telegraph poles or semaphores, which would rip the catcher arm off the train. Too late, and they would miss an exchange.

Which of the following is TRUE according to the passage?

A. The clerk booted out the outgoing mailbag before snatching the incoming bag.

B. Clerks couldn’t often see what they were doing.

C. The Railway Mail clerk’s job was considered elite because it was safe and exciting.

D. Despite their success, railway mail clerks only handled a small proportion of all non-local mail.

Mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions.
Learning English isn’t so difficult, once you get______it.

A. down to

B. get off

C. get on

D. down with

Read the following passage on transport, and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 1 to 7.

(1) The protozoans, minute, aquatic creatures each of which consists of a single cell of protoplasm, constitute a classification of the most primitive forms of animal life. They are fantastically diverse, but three major groups may be identified on the basis of their motility. The Mastigophora have one or more long tails, which they use to project themselves forward. The Ciliata, which use the same basic means for locomotion as the Mastigophora, have a larger number of short tails. The Sarcodina, which include amoebae, float or row themselves about on their crusted bodies.

(2) In addition to their form of movement, several other features discriminate among the three groups of protozoans. For example, at least two nuclei per cell have been identified in the Ciliata, usually a large nucleus that regulates growth but decomposes during reproduction, and a smaller one that contains the genetic code necessary to generate the large nucleus.

(3) Protozoans are considered animals because, unlike pigmented plants to which some protozoans are otherwise almost identical, they do not live on simple organic compounds. Their cell demonstrates all of the major characteristics of the cells of higher animals.

(4) Many species of protozoans collect into colonies, physically connected to each other and responding uniformly to outside stimulae. Current research into this phenomenon, along with investigations carried out with advanced microscopes may necessitate a redefinition of what constitutes protozoans, even calling into question the basic premise that they have only one cell. Nevertheless, with the current data available, almost 40,000 species of protozoans have been identified. No doubt, as the technology improves our methods of observation, better models of classification will be proposed.

Which of the following statements are NOT true of protozoans?

A. There are approximately 40,000 species.

B. They are the most primitive forms of animal life.

C. They have a large cell and a smaller cell.

D. They are difficult to observe.

If someone is down to earth, he is very ______.

A. practical

B. shy

C. sad

D. strange