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Bài 15: Cách mạng tháng Mười Nga và cuộc đấu tranh bảo vệ cách mạng (1917 - 1921)

Vì sao nhân dân Xô viết bảo vệ được những thành quả của Cách mạng tháng Mười ?

Lịch sử Lớp 8
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Tuyển tập đề thi thử Tiếng Anh cực hay có lời giải (Đề số 11)

Read the following passage and mark the letter A, B, C or D to indicate the correct answer to each of the questions from 43 to 50. New surveys suggest that the technological tools we use to make our lives easier are killing our leisure time. We are working longer hours, taking fewer and shorter vacations (and when we do go away, we take our cell phones, PDAs, and laptops along). And, we are more stressed than ever as increased use of e-mail, voice mail, cell phones, and the Internet is destroying any idea of privacy and leisure. Since the Industrial Revolution, people have assumed that new labor-saving devices would free them from the burdens of the workplace and give them more time to grow intellectually, creatively, and socially - exploring the arts, keeping up with current events, spending more time with friends and family, and even just "goofing off". But here we are at the start of the 21st century, enjoying one of the greatest technological boom times in human history, and nothing could be further from the truth. The very tools that were supposed to liberate us have bound us to our work and study in ways that were inconceivable just a few years ago. It would seem that technology almost never does what we expect. In “the old days”, the lines between work and leisure time were markedly clearer. People left their offices at a predictable time, were often completely disconnected from and out of touch with their jobs as they traveled to and from work, and were off-duty once they were home. That is no longer true. In today's highly competitive job market, employers demand increased productivity, expecting workers to put in longer hours and to keep in touch almost constantly via fax, cell phones, e-mail, or other communications devices. As a result, employees feel the need to check in on what is going on at the office, even on days off. They feel pressured to work after hours just to catch up on everything they have to do. Workers work harder and longer, change their work tasks more frequently, and have more and more reasons to worry about job security. Bosses, colleagues, family members, lovers, and friends expect instant responses to voice mail and e-mail messages. Even college students have become bound to their desks by an environment in which faculty, friends, and other members of the college community increasingly do their work online. Studies of time spent on instant messaging services would probably show staggering use. This is not what technology was supposed to be doing for us. New technologies, from genetic research to the Internet, offer all sorts of benefits and opportunities. But, when new tools make life more difficult and stressful rather than easier and more meaningful - and we are, as a society, barely conscious of it - then something has gone seriously awry, both with our expectations for technology and our understanding of how it should benefit us. (From "Summit 1" by Joan Saslow & Allen Ascher) Question 50: With the phrase “at a predictable time”, the author implies that

Tiếng Anh Tốt nghiệp THPT
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Bài 15: Cách mạng tháng Mười Nga và cuộc đấu tranh bảo vệ cách mạng (1917 - 1921)

“Sắc lệnh hòa bình” và “Sắc lệnh ruộng đất” đem lại những quyền lượi gì cho quần chúng nhân dân ?

Lịch sử Lớp 8
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20 Bộ đề Chinh phục điểm 9-10 môn Sinh Học cực hay có lời giải (Đề số 4)

Cho chuột đuôi ngắn, cong lai với đuôi dài thẳng. F1 toàn đuôi ngắn cong. Cho các con F1 lai với nhau được F2 với số lượng như sau: 203 chuột đuôi ngắn cong; 53 chuột dài thẳng; 7 chuột ngắn thẳng; 7 chuột dài, cong. Biết rằng mỗi tính trạng do 1 gen quy định, 2 gen quy định 2 tính trạng nằm trên cùng 1 NST. Nếu có HVG chỉ xảy ra ở con chuột cái. Ở F2 có 1 số con chuột mang gen đồng hợp lăn chết trong giai đoạn phôi. Số chuột đồng hợp lặn chết trong giai đoạn phôi là:

Sinh học Tốt nghiệp THPT
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TÍNH CHẤT HÓA HỌC CỦA CACBOHIĐRAT

Cho các gluxit (cacbohiđrat): saccarozơ, fructozơ, tinh bột, xenlulozơ. Số gluxit khi thuỷ phân trong môi trường axit tạo ra glucozơ là:

Hóa học Tốt nghiệp THPT
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Bài 15: Cách mạng tháng Mười Nga và cuộc đấu tranh bảo vệ cách mạng (1917 - 1921)

Trình bày diễn biến chính của cuộc khởi nghĩa vũ trang ở Pê-tơ-rô-grat.

Lịch sử Lớp 8
Xem chi tiết 3.7 K lượt xem 1 năm trước
20 Đề thi thử THPTQG môn Tiếng Anh cực hay có đáp án (Đề số 12)

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 from 35 to 42.         The main cause of tooth decay is acid, which is produced by bacteria in the mouth. The acid removes minerals from tooth enamel, allowing tooth decay to begin; the saliva in your mouth encourages remineralization and neutralizes the acid. The rate at which bacteria in the mouth produce acid depends on the amount of plaque on the teeth, the composition of the microbial flora, and whether the bacteria of the plaque have been “primed” by frequent exposure to sugar. To keep your teeth healthy, a regular dental hygiene program should be followed.         Removing plaque with a toothbrush and dental floss temporarily reduces the numbers of bacteria in the mouth and thus reduces tooth decay. It also makes the surfaces of the teeth more accessible, enabling saliva to neutralize acid and remineralize lesions. If fluoride is present in drinking water when teeth are forming, some fluoride is incorporated into the enamel of the teeth, making them more resistant to attack by acid. Fluoride toothpaste seems to act in another way, by promoting the remineralization of early carious lesions.                    In addition to a regular dental hygiene program, a good way to keep your teeth healthy is to reduce your intake of sweet food. The least cavity-causing way to eat sweets is to have them with meals and not between. The number of times you eat sweets rather than the total amount determines how much harmful acid the bacteria in your saliva produce. But the amount of sweets influences the quality of your saliva. Avoid, if you can, sticky sweets that stay in your mouth a long time. Also try to brush and floss your teeth after eating sugary foods. Even rinsing your mouth with water is effective. Whenever possible, eat foods with fiber, such as raw carrot sticks, apples, celery sticks, etc., that scrape off plaque, acting as a toothbrush. Cavities can be greatly reduced if these rules are followed when eating sweets. The word “scrape off” in line 29 is closest in meaning to _________.

Tiếng Anh Tốt nghiệp THPT
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Bài 15: Cách mạng tháng Mười Nga và cuộc đấu tranh bảo vệ cách mạng (1917 - 1921)

Cách mạng dân chủ tư sản tháng Hai đã làm được những việc gì ?

Lịch sử Lớp 8
Xem chi tiết 6.1 K lượt xem 1 năm trước
Bài 15: Cách mạng tháng Mười Nga và cuộc đấu tranh bảo vệ cách mạng (1917 - 1921)

Cách mạng dân chủ tư sản tháng Hai đã làm được những việc gì ?

Lịch sử Lớp 8
Xem chi tiết 1 K lượt xem 6 năm trước
Tuyển tập đề thi thử Tiếng Anh cực hay có lời giải (Đề số 11)

Read the following passage and mark the letter A, B, C or D to indicate the correct answer to each of the questions from 43 to 50. New surveys suggest that the technological tools we use to make our lives easier are killing our leisure time. We are working longer hours, taking fewer and shorter vacations (and when we do go away, we take our cell phones, PDAs, and laptops along). And, we are more stressed than ever as increased use of e-mail, voice mail, cell phones, and the Internet is destroying any idea of privacy and leisure. Since the Industrial Revolution, people have assumed that new labor-saving devices would free them from the burdens of the workplace and give them more time to grow intellectually, creatively, and socially - exploring the arts, keeping up with current events, spending more time with friends and family, and even just "goofing off". But here we are at the start of the 21st century, enjoying one of the greatest technological boom times in human history, and nothing could be further from the truth. The very tools that were supposed to liberate us have bound us to our work and study in ways that were inconceivable just a few years ago. It would seem that technology almost never does what we expect. In “the old days”, the lines between work and leisure time were markedly clearer. People left their offices at a predictable time, were often completely disconnected from and out of touch with their jobs as they traveled to and from work, and were off-duty once they were home. That is no longer true. In today's highly competitive job market, employers demand increased productivity, expecting workers to put in longer hours and to keep in touch almost constantly via fax, cell phones, e-mail, or other communications devices. As a result, employees feel the need to check in on what is going on at the office, even on days off. They feel pressured to work after hours just to catch up on everything they have to do. Workers work harder and longer, change their work tasks more frequently, and have more and more reasons to worry about job security. Bosses, colleagues, family members, lovers, and friends expect instant responses to voice mail and e-mail messages. Even college students have become bound to their desks by an environment in which faculty, friends, and other members of the college community increasingly do their work online. Studies of time spent on instant messaging services would probably show staggering use. This is not what technology was supposed to be doing for us. New technologies, from genetic research to the Internet, offer all sorts of benefits and opportunities. But, when new tools make life more difficult and stressful rather than easier and more meaningful - and we are, as a society, barely conscious of it - then something has gone seriously awry, both with our expectations for technology and our understanding of how it should benefit us. (From "Summit 1" by Joan Saslow & Allen Ascher) Question 49: Which of the following could be the main idea of the fifth paragraph?

Tiếng Anh Tốt nghiệp THPT
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TÍNH CHẤT HÓA HỌC CỦA CACBOHIĐRAT

Cho dãy các chất: glucozơ, saccarozơ, xenlulozơ, tinh bột. Số chất trong dãy không tham gia phản ứng thủy phân là

Hóa học Tốt nghiệp THPT
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Các định luật bảo toàn trong hóa học

Cho hơi nước đi qua than nóng đỏ thu được hỗn hợp X gồm CO2; CO; H2; H2O. Dẫn X đi qua 25,52 gam hỗn hợp Fe3O4 và FeCO3 nung nóng thu được chất rắn Y gồm Fe; FeO; Fe3O4; hơi nước và 0,2 mol CO2. Chia Y làm hai phần bằng nhau: Phần một hòa tan hết trong dung dịch chứa a mol HNO3 và 0,025 mol H2SO4 thu được 0,1 mol khí NO duy nhất. Phần hai hòa tan hết trong dung dịch H2SO4 đặc nóng thu được dung dịch Z chứa hai muối có số mol bằng nhau và 0,15 mol khí SO2 duy nhất. Giá trị của a là

Hóa học Lớp 11
Xem chi tiết 1.3 K lượt xem 6 năm trước
20 Bộ đề Chinh phục điểm 9-10 môn Sinh Học cực hay có lời giải (Đề số 4)

Tính trạng do gen thuộc vùng không tương đồng nằm trên NST giới tính X quy định có bao nhiêu đặc điểm phù hợp trong các đặc điểm sau đây? (1) Tính trạng lặn dễ biểu hiện ở giới dị giao. (2) Có hiện tượng di truyền chéo. (3) Tính trạng lặn không bao giờ biểu hiện ở giới đồng giao. (4) Lai thuận và lai nghịch có thể cho kết quả khác nhau. (5) Mẹ (XX) dị hợp sẽ luôn sinh ra hai dạng con đực với tỉ lệ ngang nhau. (6) Bố (XY) bị bệnh sẽ sinh ra tất cả các con đực đều không bị bệnh

Sinh học Tốt nghiệp THPT
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Bài 15: Cách mạng tháng Mười Nga và cuộc đấu tranh bảo vệ cách mạng (1917 - 1921)

Nêu những nét chính về tình hình nước Nga trước thế kỉ XX.

Lịch sử Lớp 8
Xem chi tiết 2.8 K lượt xem 1 năm trước
20 Đề thi thử THPTQG môn Tiếng Anh cực hay có đáp án (Đề số 12)

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 from 35 to 42.         The main cause of tooth decay is acid, which is produced by bacteria in the mouth. The acid removes minerals from tooth enamel, allowing tooth decay to begin; the saliva in your mouth encourages remineralization and neutralizes the acid. The rate at which bacteria in the mouth produce acid depends on the amount of plaque on the teeth, the composition of the microbial flora, and whether the bacteria of the plaque have been “primed” by frequent exposure to sugar. To keep your teeth healthy, a regular dental hygiene program should be followed.         Removing plaque with a toothbrush and dental floss temporarily reduces the numbers of bacteria in the mouth and thus reduces tooth decay. It also makes the surfaces of the teeth more accessible, enabling saliva to neutralize acid and remineralize lesions. If fluoride is present in drinking water when teeth are forming, some fluoride is incorporated into the enamel of the teeth, making them more resistant to attack by acid. Fluoride toothpaste seems to act in another way, by promoting the remineralization of early carious lesions.                    In addition to a regular dental hygiene program, a good way to keep your teeth healthy is to reduce your intake of sweet food. The least cavity-causing way to eat sweets is to have them with meals and not between. The number of times you eat sweets rather than the total amount determines how much harmful acid the bacteria in your saliva produce. But the amount of sweets influences the quality of your saliva. Avoid, if you can, sticky sweets that stay in your mouth a long time. Also try to brush and floss your teeth after eating sugary foods. Even rinsing your mouth with water is effective. Whenever possible, eat foods with fiber, such as raw carrot sticks, apples, celery sticks, etc., that scrape off plaque, acting as a toothbrush. Cavities can be greatly reduced if these rules are followed when eating sweets. What can be concluded from the passage about sweets?

Tiếng Anh Tốt nghiệp THPT
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Bộ đề luyện thi THPTQG Sinh học cực hay có lời giải chi tiết (đề số 22)

Một quần thể có thành phần kiểu gen 0,36AA : 0,48Aa : 0,16aa. Nhận định nào dưới đây là sai?

Sinh học Tốt nghiệp THPT
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TÍNH CHẤT HÓA HỌC CỦA CACBOHIĐRAT

Phát biểu nào sau đây là đúng?

Hóa học Tốt nghiệp THPT
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Tuyển tập đề thi thử Tiếng Anh cực hay có lời giải (Đề số 11)

Read the following passage and mark the letter A, B, C or D to indicate the correct answer to each of the questions from 43 to 50. New surveys suggest that the technological tools we use to make our lives easier are killing our leisure time. We are working longer hours, taking fewer and shorter vacations (and when we do go away, we take our cell phones, PDAs, and laptops along). And, we are more stressed than ever as increased use of e-mail, voice mail, cell phones, and the Internet is destroying any idea of privacy and leisure. Since the Industrial Revolution, people have assumed that new labor-saving devices would free them from the burdens of the workplace and give them more time to grow intellectually, creatively, and socially - exploring the arts, keeping up with current events, spending more time with friends and family, and even just "goofing off". But here we are at the start of the 21st century, enjoying one of the greatest technological boom times in human history, and nothing could be further from the truth. The very tools that were supposed to liberate us have bound us to our work and study in ways that were inconceivable just a few years ago. It would seem that technology almost never does what we expect. In “the old days”, the lines between work and leisure time were markedly clearer. People left their offices at a predictable time, were often completely disconnected from and out of touch with their jobs as they traveled to and from work, and were off-duty once they were home. That is no longer true. In today's highly competitive job market, employers demand increased productivity, expecting workers to put in longer hours and to keep in touch almost constantly via fax, cell phones, e-mail, or other communications devices. As a result, employees feel the need to check in on what is going on at the office, even on days off. They feel pressured to work after hours just to catch up on everything they have to do. Workers work harder and longer, change their work tasks more frequently, and have more and more reasons to worry about job security. Bosses, colleagues, family members, lovers, and friends expect instant responses to voice mail and e-mail messages. Even college students have become bound to their desks by an environment in which faculty, friends, and other members of the college community increasingly do their work online. Studies of time spent on instant messaging services would probably show staggering use. This is not what technology was supposed to be doing for us. New technologies, from genetic research to the Internet, offer all sorts of benefits and opportunities. But, when new tools make life more difficult and stressful rather than easier and more meaningful - and we are, as a society, barely conscious of it - then something has gone seriously awry, both with our expectations for technology and our understanding of how it should benefit us. (From "Summit 1" by Joan Saslow & Allen Ascher) Question 48: Which of the following could best serve as the title of the passage?

Tiếng Anh Tốt nghiệp THPT
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Các định luật bảo toàn trong hóa học

Hòa tan hết 31,36 gam hỗn hợp rắn X gồm Mg, Fe, Fe3O4 và FeCO3 vào dung dịch chứa H2SO4 và NaNO3, thu được 4,48 lít (đktc) hỗn hợp khí Y (gồm CO2, NO, N2, H2) có khối lượng 5,14 gam và dung dịch Z chỉ chứa các muối trung hòa. Dung dịch Z phản ứng tối đa với 1,285 mol NaOH, thu được 46,54 gam kết tủa và 0,56 lít khí (đktc). Nếu cho Z tác dụng với dung dịch BaCl2 dư thì thu được 166,595 gam kết tủa. Biết các phản ứng xảy ra hoàn toàn. Phần trăm khối lượng Fe3O4 trong X là

Hóa học Lớp 11
Xem chi tiết 538 lượt xem 6 năm trước
20 Bộ đề Chinh phục điểm 9-10 môn Sinh Học cực hay có lời giải (Đề số 4)

Cho biết các bước của một quy trình như sau: (1) Trồng những cây này trong điều kiện môi trường khác nhau (2) Theo dõi ghi nhận biều hiện của các tính trạng ở những cây trồng này. (3) Tạo ra được các cá thể sinh vật có cùng một kiểu gen. (4) Xác định số kiểu hình tương ứng với những điều kiện môi trường cụ thể. Để xác định mức phản ứng của một kiểu gen quy định 1 tính trạng nào đo ở cây trồng, người ta phải thực hiện theo trình tự

Sinh học Tốt nghiệp THPT
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TÍNH CHẤT HÓA HỌC CỦA CACBOHIĐRAT

Phát biểu nào dưới đây không chính xác?

Hóa học Tốt nghiệp THPT
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TÍNH CHẤT HÓA HỌC CỦA CACBOHIĐRAT

Dãy các chất nào dưới đây đều phản ứng được với Cu(OH)2 ở điều kiện thường?

Hóa học Tốt nghiệp THPT
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Tuyển tập đề thi thử Tiếng Anh cực hay có lời giải (Đề số 11)

Read the following passage and mark the letter A, B, C or D to indicate the correct answer to each of the questions from 43 to 50. New surveys suggest that the technological tools we use to make our lives easier are killing our leisure time. We are working longer hours, taking fewer and shorter vacations (and when we do go away, we take our cell phones, PDAs, and laptops along). And, we are more stressed than ever as increased use of e-mail, voice mail, cell phones, and the Internet is destroying any idea of privacy and leisure. Since the Industrial Revolution, people have assumed that new labor-saving devices would free them from the burdens of the workplace and give them more time to grow intellectually, creatively, and socially - exploring the arts, keeping up with current events, spending more time with friends and family, and even just "goofing off". But here we are at the start of the 21st century, enjoying one of the greatest technological boom times in human history, and nothing could be further from the truth. The very tools that were supposed to liberate us have bound us to our work and study in ways that were inconceivable just a few years ago. It would seem that technology almost never does what we expect. In “the old days”, the lines between work and leisure time were markedly clearer. People left their offices at a predictable time, were often completely disconnected from and out of touch with their jobs as they traveled to and from work, and were off-duty once they were home. That is no longer true. In today's highly competitive job market, employers demand increased productivity, expecting workers to put in longer hours and to keep in touch almost constantly via fax, cell phones, e-mail, or other communications devices. As a result, employees feel the need to check in on what is going on at the office, even on days off. They feel pressured to work after hours just to catch up on everything they have to do. Workers work harder and longer, change their work tasks more frequently, and have more and more reasons to worry about job security. Bosses, colleagues, family members, lovers, and friends expect instant responses to voice mail and e-mail messages. Even college students have become bound to their desks by an environment in which faculty, friends, and other members of the college community increasingly do their work online. Studies of time spent on instant messaging services would probably show staggering use. This is not what technology was supposed to be doing for us. New technologies, from genetic research to the Internet, offer all sorts of benefits and opportunities. But, when new tools make life more difficult and stressful rather than easier and more meaningful - and we are, as a society, barely conscious of it - then something has gone seriously awry, both with our expectations for technology and our understanding of how it should benefit us. (From "Summit 1" by Joan Saslow & Allen Ascher) Question 47: The word “inconceivable” in the passage is closest in meaning to “________”. 

Tiếng Anh Tốt nghiệp THPT
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20 Đề thi thử THPTQG môn Tiếng Anh cực hay có đáp án (Đề số 12)

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 from 35 to 42.         The main cause of tooth decay is acid, which is produced by bacteria in the mouth. The acid removes minerals from tooth enamel, allowing tooth decay to begin; the saliva in your mouth encourages remineralization and neutralizes the acid. The rate at which bacteria in the mouth produce acid depends on the amount of plaque on the teeth, the composition of the microbial flora, and whether the bacteria of the plaque have been “primed” by frequent exposure to sugar. To keep your teeth healthy, a regular dental hygiene program should be followed.         Removing plaque with a toothbrush and dental floss temporarily reduces the numbers of bacteria in the mouth and thus reduces tooth decay. It also makes the surfaces of the teeth more accessible, enabling saliva to neutralize acid and remineralize lesions. If fluoride is present in drinking water when teeth are forming, some fluoride is incorporated into the enamel of the teeth, making them more resistant to attack by acid. Fluoride toothpaste seems to act in another way, by promoting the remineralization of early carious lesions.                    In addition to a regular dental hygiene program, a good way to keep your teeth healthy is to reduce your intake of sweet food. The least cavity-causing way to eat sweets is to have them with meals and not between. The number of times you eat sweets rather than the total amount determines how much harmful acid the bacteria in your saliva produce. But the amount of sweets influences the quality of your saliva. Avoid, if you can, sticky sweets that stay in your mouth a long time. Also try to brush and floss your teeth after eating sugary foods. Even rinsing your mouth with water is effective. Whenever possible, eat foods with fiber, such as raw carrot sticks, apples, celery sticks, etc., that scrape off plaque, acting as a toothbrush. Cavities can be greatly reduced if these rules are followed when eating sweets. The word “it” in the second paragraph refers to _________.

Tiếng Anh Tốt nghiệp THPT
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20 Bộ đề Chinh phục điểm 9-10 môn Sinh Học cực hay có lời giải (Đề số 4)

Trạng thái cân bằng di truyền của quần thể là trạng thái mà

Sinh học Tốt nghiệp THPT
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Các định luật bảo toàn trong hóa học

Cho hỗn hợp X chứa Mg; FeO; Fe(OH)2; Cu; FeCO3 trong đó các kim loại đơn chất chiếm 31,683% về khối lượng. Hòa tan hoàn toàn 28,28 gam X trong dung dịch Y chứa 0,21 mol KNO3 và 1,16 mol HCl thu được dung dịch Z chỉ chứa các muối clorua; nitrat của kim loại và hỗn hợp khí A chứa 0,03 mol CO2 và z mol N2. Thêm NaOH vừa đủ vào Z, lọc bỏ phần kết tủa thì thu được dung dịch T chứa 78,87 gam muối. Biết Z không phản ứng với HCl. Phần trăm khối lượng Fe(OH)2 trong X gần nhất với giá trị nào sau đây?

Hóa học Lớp 11
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TÍNH CHẤT HÓA HỌC CỦA CACBOHIĐRAT

Saccarozơ và glucozơ đều có

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20 Bộ đề Chinh phục điểm 9-10 môn Sinh Học cực hay có lời giải (Đề số 4)

Nhân tố sinh thái nào bị chi phối bởi mật độ cá thể của quần thể?

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20 Đề thi thử THPTQG môn Tiếng Anh cực hay có đáp án (Đề số 12)

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 from 35 to 42.         The main cause of tooth decay is acid, which is produced by bacteria in the mouth. The acid removes minerals from tooth enamel, allowing tooth decay to begin; the saliva in your mouth encourages remineralization and neutralizes the acid. The rate at which bacteria in the mouth produce acid depends on the amount of plaque on the teeth, the composition of the microbial flora, and whether the bacteria of the plaque have been “primed” by frequent exposure to sugar. To keep your teeth healthy, a regular dental hygiene program should be followed.         Removing plaque with a toothbrush and dental floss temporarily reduces the numbers of bacteria in the mouth and thus reduces tooth decay. It also makes the surfaces of the teeth more accessible, enabling saliva to neutralize acid and remineralize lesions. If fluoride is present in drinking water when teeth are forming, some fluoride is incorporated into the enamel of the teeth, making them more resistant to attack by acid. Fluoride toothpaste seems to act in another way, by promoting the remineralization of early carious lesions.                    In addition to a regular dental hygiene program, a good way to keep your teeth healthy is to reduce your intake of sweet food. The least cavity-causing way to eat sweets is to have them with meals and not between. The number of times you eat sweets rather than the total amount determines how much harmful acid the bacteria in your saliva produce. But the amount of sweets influences the quality of your saliva. Avoid, if you can, sticky sweets that stay in your mouth a long time. Also try to brush and floss your teeth after eating sugary foods. Even rinsing your mouth with water is effective. Whenever possible, eat foods with fiber, such as raw carrot sticks, apples, celery sticks, etc., that scrape off plaque, acting as a toothbrush. Cavities can be greatly reduced if these rules are followed when eating sweets. We can infer from the passage that one benefit of fluoride to healthy teeth is _________ .

Tiếng Anh Tốt nghiệp THPT
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TÍNH CHẤT HÓA HỌC CỦA CACBOHIĐRAT

Glucozơ và fructozơ đều

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Tuyển tập đề thi thử Tiếng Anh cực hay có lời giải (Đề số 11)

Read the following passage and mark the letter A, B, C or D to indicate the correct answer to each of the questions from 43 to 50. New surveys suggest that the technological tools we use to make our lives easier are killing our leisure time. We are working longer hours, taking fewer and shorter vacations (and when we do go away, we take our cell phones, PDAs, and laptops along). And, we are more stressed than ever as increased use of e-mail, voice mail, cell phones, and the Internet is destroying any idea of privacy and leisure. Since the Industrial Revolution, people have assumed that new labor-saving devices would free them from the burdens of the workplace and give them more time to grow intellectually, creatively, and socially - exploring the arts, keeping up with current events, spending more time with friends and family, and even just "goofing off". But here we are at the start of the 21st century, enjoying one of the greatest technological boom times in human history, and nothing could be further from the truth. The very tools that were supposed to liberate us have bound us to our work and study in ways that were inconceivable just a few years ago. It would seem that technology almost never does what we expect. In “the old days”, the lines between work and leisure time were markedly clearer. People left their offices at a predictable time, were often completely disconnected from and out of touch with their jobs as they traveled to and from work, and were off-duty once they were home. That is no longer true. In today's highly competitive job market, employers demand increased productivity, expecting workers to put in longer hours and to keep in touch almost constantly via fax, cell phones, e-mail, or other communications devices. As a result, employees feel the need to check in on what is going on at the office, even on days off. They feel pressured to work after hours just to catch up on everything they have to do. Workers work harder and longer, change their work tasks more frequently, and have more and more reasons to worry about job security. Bosses, colleagues, family members, lovers, and friends expect instant responses to voice mail and e-mail messages. Even college students have become bound to their desks by an environment in which faculty, friends, and other members of the college community increasingly do their work online. Studies of time spent on instant messaging services would probably show staggering use. This is not what technology was supposed to be doing for us. New technologies, from genetic research to the Internet, offer all sorts of benefits and opportunities. But, when new tools make life more difficult and stressful rather than easier and more meaningful - and we are, as a society, barely conscious of it - then something has gone seriously awry, both with our expectations for technology and our understanding of how it should benefit us. (From "Summit 1" by Joan Saslow & Allen Ascher) Question 46: It can be inferred from the fourth paragraph that ___________.

Tiếng Anh Tốt nghiệp THPT
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Các định luật bảo toàn trong hóa học

Nung m gam hỗn hợp A gồm Mg, FeCO3, FeS, Cu(NO3)2 (Oxi chiếm 47,818% về khối lượng) một thời gian (muối nitrat bị nhiệt phân hoàn toàn) thì thu được chất rắn B và 11,144 lít hỗn hợp khí gồm CO2, NO2, O2, SO2. B phản ứng với HNO3 đặc nóng dư (thấy có 0,67 mol HNO3 phản ứng) thu được dung dịch C và 0,13 mol NO2, 0,01 mol CO2. C tác dụng với BaCl2 dư thấy xuất hiện 2,33 gam kết tủa. Biết các khí đo ở đktc, NO2 là sản phẩm khử duy nhất của N+5 Giá trị của m gần nhất với giá trị nào sau đây?

Hóa học Lớp 11
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20 Bộ đề Chinh phục điểm 9-10 môn Sinh Học cực hay có lời giải (Đề số 4)

Theo quan niệm hiện đại thì cơ thể sống xuất hiện đầu tiên trên trái đất là

Sinh học Tốt nghiệp THPT
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TÍNH CHẤT HÓA HỌC CỦA CACBOHIĐRAT

Dung dịch phản ứng được với Cu(OH)2 ở nhiệt thường tạo thành dung dịch có màu xanh lam là

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Xem chi tiết 5.2 K lượt xem 5 năm trước
Các định luật bảo toàn trong hóa học

Hòa tan hoàn toàn m gam hỗn hợp X gồm FeO, Fe3O4, Fe(OH)2, FeCO3 (trong đó Fe3O4 chiếm 25% số mol hỗn hợp) bằng dung dịch HNO3 dư, khi phản ứng hoàn toàn thu được dung dịch Y chứa (m+ 284,4)() gam muối và 15,68 lít (đktc) hỗn hợp khí Z gồm NO và CO2. Tỉ khối của Z so với H2 bằng 18. Biết NO là sản phẩm khử duy nhất của N+5  Giá trị của m là

Hóa học Lớp 11
Xem chi tiết 837 lượt xem 6 năm trước
Tuyển tập đề thi thử Tiếng Anh cực hay có lời giải (Đề số 11)

Read the following passage and mark the letter A, B, C or D to indicate the correct answer to each of the questions from 43 to 50. New surveys suggest that the technological tools we use to make our lives easier are killing our leisure time. We are working longer hours, taking fewer and shorter vacations (and when we do go away, we take our cell phones, PDAs, and laptops along). And, we are more stressed than ever as increased use of e-mail, voice mail, cell phones, and the Internet is destroying any idea of privacy and leisure. Since the Industrial Revolution, people have assumed that new labor-saving devices would free them from the burdens of the workplace and give them more time to grow intellectually, creatively, and socially - exploring the arts, keeping up with current events, spending more time with friends and family, and even just "goofing off". But here we are at the start of the 21st century, enjoying one of the greatest technological boom times in human history, and nothing could be further from the truth. The very tools that were supposed to liberate us have bound us to our work and study in ways that were inconceivable just a few years ago. It would seem that technology almost never does what we expect. In “the old days”, the lines between work and leisure time were markedly clearer. People left their offices at a predictable time, were often completely disconnected from and out of touch with their jobs as they traveled to and from work, and were off-duty once they were home. That is no longer true. In today's highly competitive job market, employers demand increased productivity, expecting workers to put in longer hours and to keep in touch almost constantly via fax, cell phones, e-mail, or other communications devices. As a result, employees feel the need to check in on what is going on at the office, even on days off. They feel pressured to work after hours just to catch up on everything they have to do. Workers work harder and longer, change their work tasks more frequently, and have more and more reasons to worry about job security. Bosses, colleagues, family members, lovers, and friends expect instant responses to voice mail and e-mail messages. Even college students have become bound to their desks by an environment in which faculty, friends, and other members of the college community increasingly do their work online. Studies of time spent on instant messaging services would probably show staggering use. This is not what technology was supposed to be doing for us. New technologies, from genetic research to the Internet, offer all sorts of benefits and opportunities. But, when new tools make life more difficult and stressful rather than easier and more meaningful - and we are, as a society, barely conscious of it - then something has gone seriously awry, both with our expectations for technology and our understanding of how it should benefit us. (From "Summit 1" by Joan Saslow & Allen Ascher) Question 45: The word “They” in the fourth paragraph refers to ___________.

Tiếng Anh Tốt nghiệp THPT
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20 Đề thi thử THPTQG môn Tiếng Anh cực hay có đáp án (Đề số 12)

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 from 35 to 42.         The main cause of tooth decay is acid, which is produced by bacteria in the mouth. The acid removes minerals from tooth enamel, allowing tooth decay to begin; the saliva in your mouth encourages remineralization and neutralizes the acid. The rate at which bacteria in the mouth produce acid depends on the amount of plaque on the teeth, the composition of the microbial flora, and whether the bacteria of the plaque have been “primed” by frequent exposure to sugar. To keep your teeth healthy, a regular dental hygiene program should be followed.         Removing plaque with a toothbrush and dental floss temporarily reduces the numbers of bacteria in the mouth and thus reduces tooth decay. It also makes the surfaces of the teeth more accessible, enabling saliva to neutralize acid and remineralize lesions. If fluoride is present in drinking water when teeth are forming, some fluoride is incorporated into the enamel of the teeth, making them more resistant to attack by acid. Fluoride toothpaste seems to act in another way, by promoting the remineralization of early carious lesions.                    In addition to a regular dental hygiene program, a good way to keep your teeth healthy is to reduce your intake of sweet food. The least cavity-causing way to eat sweets is to have them with meals and not between. The number of times you eat sweets rather than the total amount determines how much harmful acid the bacteria in your saliva produce. But the amount of sweets influences the quality of your saliva. Avoid, if you can, sticky sweets that stay in your mouth a long time. Also try to brush and floss your teeth after eating sugary foods. Even rinsing your mouth with water is effective. Whenever possible, eat foods with fiber, such as raw carrot sticks, apples, celery sticks, etc., that scrape off plaque, acting as a toothbrush. Cavities can be greatly reduced if these rules are followed when eating sweets. According to the passage, all of the following statements about plaque are true EXCEPT _________.

Tiếng Anh Tốt nghiệp THPT
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20 Bộ đề Chinh phục điểm 9-10 môn Sinh Học cực hay có lời giải (Đề số 4)

Một gen có 4050 liên kết hiđrô, tổng phần trăm giữa G với một loại nuclêôtit khác là 70%. Trên mạch đơn thứ nhất của gen có A + G = 40% số nuclêôtit của mạch và X – T là 20% số nuclêôtit của mạch.Số nuclêôtit loại A trên một mạch của gen là:

Sinh học Tốt nghiệp THPT
Xem chi tiết 5.9 K lượt xem 6 năm trước
Các định luật bảo toàn trong hóa học

Nung nóng m gam hỗn hợp H gồm Cu, CU(NO3)2, Fe, Fe(NO3)2, Fe(NO3)3, thu được hỗn hợp rắn X và 8,96 lít một khí Z (đktc). Cho toàn bộ X tác dụng với dung dịch HNO3 dư, thu được 4,032 lít khí NO (đktc, sản phẩm khử duy nhất) và dung dịch Y. Cho lượng dư dung dịch NaOH vào Y được kết tủa T. Nung T trong không khí đến khối lượng không đổi được 41,6 gam rắn. Biết các phản ứng xảy ra hoàn toàn. Giá trị của m là

Hóa học Lớp 11
Xem chi tiết 3.1 K lượt xem 6 năm trước
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Dẫn luồng khí CO qua hỗn hợp X gồm CuO, Fe2O3 nung nóng một thời gian thu được chất rắn Y và hỗn hợp khí Z. Hấp thụ Z vào bình đựng Ca(OH)2 dư thu được 24 gam kết tủa. Hòa tan hoàn toàn Y trong dung dịch HNO3 vừa đủ thì thu được hỗn hợp khí gồm 0,11 mol NO và 0,07 mol NO2. Khối lượng muối Fe(NO3)2 trong T là

Hóa học Lớp 11
Xem chi tiết 314 lượt xem 6 năm trước
20 Bộ đề Chinh phục điểm 9-10 môn Sinh Học cực hay có lời giải (Đề số 4)

Trong các cơ chế di truyền ở cấp độ phân tử, đặc điểm nào sau đây có ở cả enzim ARN – pôlimeraza và enzim ADN – pôlimeraza? (1) Có khả năng tháo xoắn phân tử ADN. (2) Có khả năng tổng hợp mạch pôlinuclêôtit mới theo chiều 5’ – 3’ mà không cần đoạn mồi. (3) Có khả năng tách hai mạch của ADN mẹ. (4) Có khả năng hoạt động trên cả hai mạch của phân tử ADN. (5) Có khả năng lắp ráp các nuclêôtit của mạch mới theo nguyên tắc bổ sung với các nuclêôtit của mạch ADN khuôn. Phương án đúng là

Sinh học Tốt nghiệp THPT
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20 Đề thi thử THPTQG môn Tiếng Anh cực hay có đáp án (Đề số 12)

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 from 35 to 42.         The main cause of tooth decay is acid, which is produced by bacteria in the mouth. The acid removes minerals from tooth enamel, allowing tooth decay to begin; the saliva in your mouth encourages remineralization and neutralizes the acid. The rate at which bacteria in the mouth produce acid depends on the amount of plaque on the teeth, the composition of the microbial flora, and whether the bacteria of the plaque have been “primed” by frequent exposure to sugar. To keep your teeth healthy, a regular dental hygiene program should be followed.         Removing plaque with a toothbrush and dental floss temporarily reduces the numbers of bacteria in the mouth and thus reduces tooth decay. It also makes the surfaces of the teeth more accessible, enabling saliva to neutralize acid and remineralize lesions. If fluoride is present in drinking water when teeth are forming, some fluoride is incorporated into the enamel of the teeth, making them more resistant to attack by acid. Fluoride toothpaste seems to act in another way, by promoting the remineralization of early carious lesions.                    In addition to a regular dental hygiene program, a good way to keep your teeth healthy is to reduce your intake of sweet food. The least cavity-causing way to eat sweets is to have them with meals and not between. The number of times you eat sweets rather than the total amount determines how much harmful acid the bacteria in your saliva produce. But the amount of sweets influences the quality of your saliva. Avoid, if you can, sticky sweets that stay in your mouth a long time. Also try to brush and floss your teeth after eating sugary foods. Even rinsing your mouth with water is effective. Whenever possible, eat foods with fiber, such as raw carrot sticks, apples, celery sticks, etc., that scrape off plaque, acting as a toothbrush. Cavities can be greatly reduced if these rules are followed when eating sweets. What does this passage mainly discuss?

Tiếng Anh Tốt nghiệp THPT
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Tuyển tập đề thi thử Tiếng Anh cực hay có lời giải (Đề số 11)

Read the following passage and mark the letter A, B, C or D to indicate the correct answer to each of the questions from 43 to 50. New surveys suggest that the technological tools we use to make our lives easier are killing our leisure time. We are working longer hours, taking fewer and shorter vacations (and when we do go away, we take our cell phones, PDAs, and laptops along). And, we are more stressed than ever as increased use of e-mail, voice mail, cell phones, and the Internet is destroying any idea of privacy and leisure. Since the Industrial Revolution, people have assumed that new labor-saving devices would free them from the burdens of the workplace and give them more time to grow intellectually, creatively, and socially - exploring the arts, keeping up with current events, spending more time with friends and family, and even just "goofing off". But here we are at the start of the 21st century, enjoying one of the greatest technological boom times in human history, and nothing could be further from the truth. The very tools that were supposed to liberate us have bound us to our work and study in ways that were inconceivable just a few years ago. It would seem that technology almost never does what we expect. In “the old days”, the lines between work and leisure time were markedly clearer. People left their offices at a predictable time, were often completely disconnected from and out of touch with their jobs as they traveled to and from work, and were off-duty once they were home. That is no longer true. In today's highly competitive job market, employers demand increased productivity, expecting workers to put in longer hours and to keep in touch almost constantly via fax, cell phones, e-mail, or other communications devices. As a result, employees feel the need to check in on what is going on at the office, even on days off. They feel pressured to work after hours just to catch up on everything they have to do. Workers work harder and longer, change their work tasks more frequently, and have more and more reasons to worry about job security. Bosses, colleagues, family members, lovers, and friends expect instant responses to voice mail and e-mail messages. Even college students have become bound to their desks by an environment in which faculty, friends, and other members of the college community increasingly do their work online. Studies of time spent on instant messaging services would probably show staggering use. This is not what technology was supposed to be doing for us. New technologies, from genetic research to the Internet, offer all sorts of benefits and opportunities. But, when new tools make life more difficult and stressful rather than easier and more meaningful - and we are, as a society, barely conscious of it - then something has gone seriously awry, both with our expectations for technology and our understanding of how it should benefit us. (From "Summit 1" by Joan Saslow & Allen Ascher) Question 44: This passage has probably been taken from __________.

Tiếng Anh Tốt nghiệp THPT
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Các định luật bảo toàn trong hóa học

Hòa tan hoàn toàn 19,36 gam hỗn hợp X gồm Fe, FeCO3, Fe2O3 bằng dung dịch HNO3 dư thu được dung dịch Z và 0,27 mol hỗn hợp khí gồm NO2, CO2. Nếu cho cùng lượng X tác dụng với dung dịch H2SO4 đặc, nóng dư thì thu được 0,165 mol hỗn hợp CO2, SO2. Phần trăm khối lượng của Fe2O3 trong X gần nhất với giá trị nào sau đây?

Hóa học Lớp 11
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Các định luật bảo toàn trong hóa học

Cho hỗn hợp X gồm Fe, Zn, Mg. Lấy m gam X phản ứng với dung dịch axit HCl dư thì thu được dung dịch Y và 0,1 mol H2. Cùng lượng X này tác dụng với HNO3 dư thì sinh ra 560 ml khí N2 (sản phẩm khử duy nhất, đktc). Khối lượng Fe trong m gam X là

Hóa học Lớp 11
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20 Bộ đề Chinh phục điểm 9-10 môn Sinh Học cực hay có lời giải (Đề số 4)

Cho biết mỗi tính trạng do 1 cặp gen quy định và gen trội là trội hoàn toàn. Xét các phép lai: (1) aaBbDd xAaBBdd.              (2) AaBbDd x aabbDd.              (3) AabbDd x aaBbdd. (4) aaBbDD x aabbDd.              (5) AaBbDD x aaBbDd.            (6) AABbdd x AabbDd. Theo lí thuyết, trong các phép lai trên, có bao nhiêu phép lai mà đời con có 4 loại kiểu hình chiếm tỉ lệ bằng nhau?

Sinh học Tốt nghiệp THPT
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Các định luật bảo toàn trong hóa học

Cho hỗn hợp X gồm Zn, Mg. Lấy m gam X phản ứng với dung dịch axit HCl dư thì thu được 0,1 mol H2. Cùng lượng X này tác dụng với HNO3 dư thì sinh ra V ml khí N2 (sản phẩm khử duy nhất, đktc). Giá trị của V là

Hóa học Lớp 11
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Tuyển tập đề thi thử Tiếng Anh cực hay có lời giải (Đề số 11)

Read the following passage and mark the letter A, B, C or D to indicate the correct answer to each of the questions from 43 to 50. New surveys suggest that the technological tools we use to make our lives easier are killing our leisure time. We are working longer hours, taking fewer and shorter vacations (and when we do go away, we take our cell phones, PDAs, and laptops along). And, we are more stressed than ever as increased use of e-mail, voice mail, cell phones, and the Internet is destroying any idea of privacy and leisure. Since the Industrial Revolution, people have assumed that new labor-saving devices would free them from the burdens of the workplace and give them more time to grow intellectually, creatively, and socially - exploring the arts, keeping up with current events, spending more time with friends and family, and even just "goofing off". But here we are at the start of the 21st century, enjoying one of the greatest technological boom times in human history, and nothing could be further from the truth. The very tools that were supposed to liberate us have bound us to our work and study in ways that were inconceivable just a few years ago. It would seem that technology almost never does what we expect. In “the old days”, the lines between work and leisure time were markedly clearer. People left their offices at a predictable time, were often completely disconnected from and out of touch with their jobs as they traveled to and from work, and were off-duty once they were home. That is no longer true. In today's highly competitive job market, employers demand increased productivity, expecting workers to put in longer hours and to keep in touch almost constantly via fax, cell phones, e-mail, or other communications devices. As a result, employees feel the need to check in on what is going on at the office, even on days off. They feel pressured to work after hours just to catch up on everything they have to do. Workers work harder and longer, change their work tasks more frequently, and have more and more reasons to worry about job security. Bosses, colleagues, family members, lovers, and friends expect instant responses to voice mail and e-mail messages. Even college students have become bound to their desks by an environment in which faculty, friends, and other members of the college community increasingly do their work online. Studies of time spent on instant messaging services would probably show staggering use. This is not what technology was supposed to be doing for us. New technologies, from genetic research to the Internet, offer all sorts of benefits and opportunities. But, when new tools make life more difficult and stressful rather than easier and more meaningful - and we are, as a society, barely conscious of it - then something has gone seriously awry, both with our expectations for technology and our understanding of how it should benefit us. (From "Summit 1" by Joan Saslow & Allen Ascher) Question 43: According to the first three paragraphs, technological tools that were designed to make our lives easier  __________.

Tiếng Anh Tốt nghiệp THPT
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20 Bộ đề Chinh phục điểm 9-10 môn Sinh Học cực hay có lời giải (Đề số 4)

Khi nói về cơ chế điều hòa theo mô hình Operon Lac ở vi khuẩn E.Coli. Nhận định nào sau đây không đúng?

Sinh học Tốt nghiệp THPT
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Các định luật bảo toàn trong hóa học

Cho hỗn hợp A gồm sắt và các oxit tương ứng. Hòa tan 47,4 gam A trong dung dịch H2SO4 đặc, nóng thu được dung dịch B chỉ chứa các muối có số mol bằng nhau và 0,3 mol khí SO2. Thêm Ba(OH)2 dư vào B thu được m gam kết tủa. Giá của m gần nhất với giá trị nào sau đây?

Hóa học Lớp 11
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