Cho hỗn hợp X gồm 0,1 mol Fe và 0,1 mol Al tác dụng với dung dịch chứa 0,2 mol CuCl₂ đến khi phản ứng hoàn toàn thấy khối lượng chất rắn tăng m gam. Giá trị của m là

Cho 5,96 gam hỗn hợp X gồm Zn và Fe vào 1 lít dung dịch   a mol/l thì thu được 16,8 gam kết tủa. Nếu cho 5,96 gam hỗn hợp X vào 2 lít dung dịch  thì thu được 28,08 gam kết tủa. Giá trị của a là:         

Để tách lấy Ag ra khỏi hỗn hợp Fe, Cu, Ag ta cần dùng lượng dư dung dịch nào sau đây?

Cho hồn hợp gồm Fe và Mg vào dung dịch , khi các phản ứng xảy ra hoàn toàn thu được dung dịch X (gồm 2 muối) và chất rắn Y (gồm 2 kim loại). Hai muối trong X là:

Trường hợp không xảy ra phản ứng hoá học là:  

Sợi dây đồng được dùng để làm dây phơi quần áo, để ngoài không khí ẩm lâu ngày bị đứt. Để nối lại mối đứt đó, ta nên dùng kim loại nào để dây được bền nhất?

Cho hỗn hợp Mg và Cu vào dung dịch HCl dư. Kết thúc phản ứng, cô cạn dung dịch thu được chất rắn gồm : 

Trong thực tế người ta thường dùng những kim loại nào sau đây để làm dây dẫn điện   

Cặp chất không xảy ra phản ứng hóa học là:

Điện phân dd chứa HCl, CuCl₂, NaCl, điện cực trơ, màng ngăn đến khi hết cả 3 chất. Kết luận nào không đúng?         

Cho hỗn hợp gồm Fe và Mg vào dung dịch AgNO3 đến khi các phản ứng xảy ra hoàn toàn, thu được dung dịch X gồm hai muối và chất rắn Y gồm hai kim loại. Hai muối trong dung dịch X là    

Cho các cặp oxi hóa – khử được sắp xếp theo chiều tăng dần tính oxi hóa của dạng oxi hóa như sau: Fe²⁺/Fe, Cu²⁺/Cu, Fe³⁺/Fe²⁺. Phát biểu nào sau đây là đúng?         

Dãy các kim loại được sắp xếp theo chiều giảm dẫn tính khử là:         

Cho hỗn hợp gồm Al và Zn vào dung dịch AgNO3. Sau khi phản ứng xảy ra hoàn toàn, thu được dung dịch X chỉ chứa một muối và phần không tan Y gồm hai kim loại. Hai kim loại trong Y và muối trong X là           

Cho nguyên tố X có Z = 20. a.       Viết cấu hình electron của nguyên tử X. X có tính kim loại hay tính phi kim. X là nguyên tố s, p, d, hay f? Vì sao? b.       Xác định vị trí của X ( số thứ tự, chu kì, nhóm) trong bảng tuần hoàn. c.       Hóa trị cao nhất trong hợp chất với Oxi. d.       Công thức của Oxit cao nhất, của hidrroxit tương ứng và tính chất của nó (tính axit,bazo).  

Cho m gam Mg vào dung dịch chứa 0,12 mol FeCl₃. Sau khi phản ứng xảy ra hoàn toàn thu được 3,36 gam chất rắn. Giá trị của m là ?         

Cho 6,88 gam hỗn hợp chứa Mg và Cu với tỷ lệ mol tương ứng là 1:5 vào dung dịch chứa 0,12 mol . Sau khi các phản ứng hoàn toàn thu được m gam kim loại. Giá trị của m là:         

Kim loại Zn có thể khử ion nào sau đây?

Cho hỗn hợp X gồm Al, Fe, Cu. Dung dịch nào sau đây (khi lấy dư) không thể hòa tan hết X?

Cho hỗn hợp bột X gồm 3 kim loại: Fe, Cu, Ag. Để tách nhanh Ag ra khỏi X mà không làm thay đổi khối lượng các chất cần dùng hóa chất nào?          

Cho m gam bột Zn vào 500 ml dung dịch Fe2(SO4)3 0,24M. Sau khi các phản ứng xảy ra hoàn toàn, khối lượng dung dịch tăng thêm 9,6 gam so với khối lượng dung dịch ban đầu. Giá trị của m là         

Cho 2,7 gam Al và 1,4 gam Fe vào 400 ml dung dịch  1M, sau khi phản ứng kết thúc thu được m gam chất rắn. Giá trị của m là:

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 31 to 35:

 Nowadays people are more aware that wildlife all over the world is in (31)___________. Many species of animals are threatened, and could easily become (32)___________ if we do not make an effort to protect them. There are many reasons for this. In some cases animals are hunted for their fur or for other valuable parts of their bodies. Some birds, such as parrots, are caught (33)___________, and sold as pets. For many animals and birds, the problem is that their habitats-the place where they live-is disappearing. More land is used for farm, for houses and industry, and there are fewer open spaces than there once were. Farmers use powerful chemicals to help them grow better crops, but these chemicals pollute the environment and (34)___________ wildlife. The most successful animals on Earth, human beings, will soon be the only ones (35)___________ unless we can solve this problem.

Question 32:  

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 41 to 45:

Reference books are not designed to be read from the first page to the last but rather to be consulted to answer the questions and provide both general and specific pieces of information. One of the most (41) ________- used reference books is a dictionary, which provides information about words. It lists meanings and spellings, (42)________how a word is pronounced, gives examples of how it is used, may reveal its origins and also lists synonyms and antonyms. To help you find the words faster, there are guide words at the top of each page showing the first and last words on the page and of course it (43) ________ to know the alphabet! There may be numerous special sections at the back with facts about famous people and places, lists of dates and scientific names, etc. There is usually a section at the front explaining how to use the dictionary, which includes the special abbreviations or signs. An atlas is also a reference book and (44) ________ charts, tables and geographical facts, as well as maps. Political maps locate countries and cities, physical maps show the formation of the land with its mountains and valleys, and economic maps show industries and agriculture. To find a specific place, you need to look in the index at the back of the atlas and the exact position on the map. There are numerous map (45) ________ that you need to know in order to be able to read a map-almost like a special language and these are explained at the front of the atlas.  

Question 45:

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 41 to 45:

Reference books are not designed to be read from the first page to the last but rather to be consulted to answer the questions and provide both general and specific pieces of information. One of the most (41) ________- used reference books is a dictionary, which provides information about words. It lists meanings and spellings, (42)________how a word is pronounced, gives examples of how it is used, may reveal its origins and also lists synonyms and antonyms. To help you find the words faster, there are guide words at the top of each page showing the first and last words on the page and of course it (43) ________ to know the alphabet! There may be numerous special sections at the back with facts about famous people and places, lists of dates and scientific names, etc. There is usually a section at the front explaining how to use the dictionary, which includes the special abbreviations or signs. An atlas is also a reference book and (44) ________ charts, tables and geographical facts, as well as maps. Political maps locate countries and cities, physical maps show the formation of the land with its mountains and valleys, and economic maps show industries and agriculture. To find a specific place, you need to look in the index at the back of the atlas and the exact position on the map. There are numerous map (45) ________ that you need to know in order to be able to read a map-almost like a special language and these are explained at the front of the atlas.  

Question 44:

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 41 to 45:

Reference books are not designed to be read from the first page to the last but rather to be consulted to answer the questions and provide both general and specific pieces of information. One of the most (41) ________- used reference books is a dictionary, which provides information about words. It lists meanings and spellings, (42)________how a word is pronounced, gives examples of how it is used, may reveal its origins and also lists synonyms and antonyms. To help you find the words faster, there are guide words at the top of each page showing the first and last words on the page and of course it (43) ________ to know the alphabet! There may be numerous special sections at the back with facts about famous people and places, lists of dates and scientific names, etc. There is usually a section at the front explaining how to use the dictionary, which includes the special abbreviations or signs. An atlas is also a reference book and (44) ________ charts, tables and geographical facts, as well as maps. Political maps locate countries and cities, physical maps show the formation of the land with its mountains and valleys, and economic maps show industries and agriculture. To find a specific place, you need to look in the index at the back of the atlas and the exact position on the map. There are numerous map (45) ________ that you need to know in order to be able to read a map-almost like a special language and these are explained at the front of the atlas.  

Question 43:

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 41 to 45:

Reference books are not designed to be read from the first page to the last but rather to be consulted to answer the questions and provide both general and specific pieces of information. One of the most (41) ________- used reference books is a dictionary, which provides information about words. It lists meanings and spellings, (42)________how a word is pronounced, gives examples of how it is used, may reveal its origins and also lists synonyms and antonyms. To help you find the words faster, there are guide words at the top of each page showing the first and last words on the page and of course it (43) ________ to know the alphabet! There may be numerous special sections at the back with facts about famous people and places, lists of dates and scientific names, etc. There is usually a section at the front explaining how to use the dictionary, which includes the special abbreviations or signs. An atlas is also a reference book and (44) ________ charts, tables and geographical facts, as well as maps. Political maps locate countries and cities, physical maps show the formation of the land with its mountains and valleys, and economic maps show industries and agriculture. To find a specific place, you need to look in the index at the back of the atlas and the exact position on the map. There are numerous map (45) ________ that you need to know in order to be able to read a map-almost like a special language and these are explained at the front of the atlas.  

Question 42:

Read the following passage and mark the letter A, B, C or D to indicate the correct word or phrase that best fits each of the numbered blanks from 31 to 35:

THE FIRST WOMAN SCIENTIST Hypatia was born in Alexandria, in Egypt, in 370 A.D. For many centuries, she was the only woman scientist to have a place in the history books. Hypatia’s father was director of Alexandria University, and he (31) ________ sure his daughter had the best education available. This was unusual, as most women then had few (32) ________ to study. After studying in Athens and Rome, Hypatia returned to Alexandria where she began teaching mathematics. She soon became famous (33) ________ her knowledge of new ideas. We have no copies of her book, but we know that she wrote several important mathematical works. Hypatia was also interested in technology and invented several scientific tools to help with her work. At the (34) ________, many rulers were afraid of science, and anyone connected with it was in danger. One day in March 415, Hypatia (35) ________ attacked in the street and killed.  

Question 31:        

Read the following passage and mark the letter A, B, C or D to indicate the correct word or phrase that best fits each of the numbered blanks from 31 to 35:

THE FIRST WOMAN SCIENTIST Hypatia was born in Alexandria, in Egypt, in 370 A.D. For many centuries, she was the only woman scientist to have a place in the history books. Hypatia’s father was director of Alexandria University, and he (31) ________ sure his daughter had the best education available. This was unusual, as most women then had few (32) ________ to study. After studying in Athens and Rome, Hypatia returned to Alexandria where she began teaching mathematics. She soon became famous (33) ________ her knowledge of new ideas. We have no copies of her book, but we know that she wrote several important mathematical works. Hypatia was also interested in technology and invented several scientific tools to help with her work. At the (34) ________, many rulers were afraid of science, and anyone connected with it was in danger. One day in March 415, Hypatia (35) ________ attacked in the street and killed.  

Question 33:        

Read the following passage and mark the letter A, B, C or D to indicate the correct word or phrase that best fits each of the numbered blanks from 31 to 35:

THE FIRST WOMAN SCIENTIST Hypatia was born in Alexandria, in Egypt, in 370 A.D. For many centuries, she was the only woman scientist to have a place in the history books. Hypatia’s father was director of Alexandria University, and he (31) ________ sure his daughter had the best education available. This was unusual, as most women then had few (32) ________ to study. After studying in Athens and Rome, Hypatia returned to Alexandria where she began teaching mathematics. She soon became famous (33) ________ her knowledge of new ideas. We have no copies of her book, but we know that she wrote several important mathematical works. Hypatia was also interested in technology and invented several scientific tools to help with her work. At the (34) ________, many rulers were afraid of science, and anyone connected with it was in danger. One day in March 415, Hypatia (35) ________ attacked in the street and killed.

Question 32:        

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 31 to 35:

All relationships go through difficult times. In the past, when married couples had problems they usually didn’t (31) _________. They had to either (32) _________ with each other or continue to live together in an unhappy relationship. Getting divorced wasn’t an option for most people due to economic and social reasons. Some people believe that this wasn’t such a bad thing. They say that relationships require hard work and (33) _________. “If a relationship is going to last a lifetime, you have to keep working at it,” says Doreen, who is celebrating her fiftieth wedding anniversary this year. “It isn’t all roses and romance. No one perfect all of the time. These days young people give up when there’s the (34) _________ argument.” Experts agree that communication is key. The most important thing is to keep talking. How many times have you heard yourself say to somebody, “If only you’d listen!” or “I wish you wouldn’t do that!” The truth is, the (35) ______ couples talk, the better their relationship can be.  

Question 31:

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 31 to 35:

All relationships go through difficult times. In the past, when married couples had problems they usually didn’t (31) _________. They had to either (32) _________ with each other or continue to live together in an unhappy relationship. Getting divorced wasn’t an option for most people due to economic and social reasons. Some people believe that this wasn’t such a bad thing. They say that relationships require hard work and (33) _________. “If a relationship is going to last a lifetime, you have to keep working at it,” says Doreen, who is celebrating her fiftieth wedding anniversary this year. “It isn’t all roses and romance. No one perfect all of the time. These days young people give up when there’s the (34) _________ argument.” Experts agree that communication is key. The most important thing is to keep talking. How many times have you heard yourself say to somebody, “If only you’d listen!” or “I wish you wouldn’t do that!” The truth is, the (35) ______ couples talk, the better their relationship can be.  

Question 33: