Hòa tan hoàn toàn hỗn hợp H gồm Mg (5a mol) và Fe3O4 (a mol) trong dung dịch chứa KNO3 và 0,725 mol HCl, cô cạn dung dịch sau phản ứng thì thu được lượng muối khan nặng hơn khối lượng hỗn hợp H là 26,23g. Biết kết thúc phản ứng thu được 0,08 mol hỗn khí Z chứa H2 và NO, tỉ khối của Z so với H2 bằng 11,5. % khối lượng sắt có trong muối khan có giá trị gần nhất với         

Thực hành thí nghiệm : nhỏ từng giọt dung dịch KMnO₄ loãng vào ống nghiệm đựng dung dịch hỗn hợp FeSO₄ và H₂SO₄ loãng, lắc nhẹ. Nêu hiện tượng xảy ra, viết và cân bằng phương trình hóa học để giải thích và cho biết vai trò của từng chất, trong phản ứng.  

Kim loại nào sau đây khi tác dụng với dung dịch HCl loãng và tác dụng với khí Cl₂ cho cùng loại muối clorua kim loại ?    

Các kim loại X, Y, Z đều không tan tan trong nước ở điều kiện thường. X và Y đều tan trong dung dịch HCl nhưng chỉ có Y tan trong dung dịch NaOH. Z không tan trong dung dịch HCl nhưng tan trong dung dịch HNO₃ loãng, đun nóng. Các kim loại X, Y, và Z tương ứng là:

Cho dãy các kim loại: Na, Ca, Cu, Fe, K. Số kim loại trong dãy tác dụng với H2O tạo dung dịch bazơ là:          

Hòa tan hoàn toàn 12 gam hỗn hợp Fe, Cu (tỉ lệ 1 :1) bằng axit HNO3, thu được V lít (ở đktc) hỗn hợp khí X (gồm NO và NO2) và dung dịch Y (chỉ chứa hai muối và axit dư). Tỉ khối của X đối với H2 bằng 19. Giá trị của V là (cho H=1, N=14, O=16, Fe=56, Cu=64)           

Phản ứng hóa học nào sau đây là đúng ?  

Hòa tan 7,8 gam hỗn hợp bột Al và Mg trong dung dịch HCl dư. Sau phản ứng khối lượng dung dịch tăng thêm 7,0 gam so với dung dịch HCl ban đầu. Khối lượng Al và Mg trong hỗn hợp ban đầu là         

Cho 3,68 gam hỗn hợp Al, Zn phản ứng với H₂SO₄ 20% (vừa đủ); thu được 0,1 mol H₂. Khối lượng thu được dung dịch sau phản ứng là ?

Hòa tan hoàn toàn 7,5 gam hỗn hợp gồm Mg và Al bằng lượng vừa đủ V lít dung dịch HNO3 1M. Sau khi các phản ứng kết thúc, thu được 0,672 lít N2 (ở đktc) duy nhất và dung dịch chứa 54,9 gam muối. Giá trị của V là         

Cho a mol Mg tác dụng với dung dịch H­2SO4 loãng dư, thu được x mol H2. Cho a mol Al tác dụng với dung dịch H­2SO4 loãng dư, thu được y mol H2. Quan hệ giữa x và y là         

Kim loại M phản ứng được với : dung dịch HCl, dung dịch AgNO3, dung dịch HNO3 (đặc, nguội). Kim loại M là

Nhúng một thanh magie vào dung dịch có chứa 0,8 mol Fe(NO3)3 và 0,05 mol Cu(NO3)2. Sau một thời gian, lấy thanh kim loại ra, rửa sạch, cân lại thấy khối lượng tăng 11,6 gam so với thanh kim loại ban đầu. Khối lượng magie đã phản ứng là :         

Tính hóa học đặc trưng của kim loại là:

Phản ứng hóa học nào sau đây sai :  

Cho hỗn hợp gồm 1,12g Fe và 1,92g Cu vào 400ml dung dịch chứa H2SO4 0,5M và NaNO3 0,2M. Sau khi các phản ứng xảy ra hoàn toàn thu được dung dịch X và khí NO duy nhất. Cho V ml dung dịch NaOH 1M vào dung dịch X thì thu được lượng kết tủa cực đại. Giá trị tối thiểu của V là           

Cho hỗn hợp Cu và Fe₂O₃ vào dung dịch HCl dư. Sau khi phản ứng xảy ra hoàn toàn, thu được dung dịch X và một lượng chất rắn không tan. Muối trong dung dịch X là

Hòa tan hoàn toàn l,18g hỗn hợp X gồm Al và Cu trong dung dịch HCl thu được 0,672 l khí (đktc). Phần trăm về khối lượng Cu trong X là?         

Phát biểu nào sau đây là đúng  

Hòa tan hoàn toàn hỗn hợp H gồm Mg (5a mol) và Fe3O4 (a mol) trong dung dịch chứa KNO3 và 0,725 mol HCl, cô cạn dung dịch sau phản ứng thì thu được lượng muối khan nặng hơn khối lượng hỗn hợp H là 26,23g. Biết kết thúc phản ứng thu được 0,08 mol hỗn khí Z chứa H2 và NO, tỉ khối của Z so với H2 bằng 11,5. % khối lượng sắt có trong muối khan có giá trị gần nhất với         

Khi nói về kim loại, phát biểu nào sau đây sai ?             

Cho dãy các kim loại: K, Mg, Cu, Al. Số kim loại trong dãy phản ứng được với dung dịch HCl 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 thet best fits each of the numbered blanks from 24 to 28:

 Personal space is a term that refers (24)______the distance we like to keep between ourselves  and other people. When (25)______we do not know well gets too close we usually begin to feel uncomfortable. If a business colleague comes closer than 1.2 meters, the most common response is to move (26_______ . Some interesting (27)______ have been done in libraries. If strangers come too close, many people get up and leave the building; others use different methods such as turning their back on the intruder. Living in cities has made people develop new skills for dealing with situations where they are very close to strangers. Most people on crowded trains try not to look at strangers; they avoid skin contact, and apologize if hands touch by mistake. People use newspapers (28)______ a barrier between themselves and other people, and if they do not have one, they stare into the distance, making sure they are not looking into anyone’s eyes.  

Question 26:

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word or phrase thet best fits each of the numbered blanks from 24 to 28:

 Personal space is a term that refers (24)______the distance we like to keep between ourselves  and other people. When (25)______we do not know well gets too close we usually begin to feel uncomfortable. If a business colleague comes closer than 1.2 meters, the most common response is to move (26_______ . Some interesting (27)______ have been done in libraries. If strangers come too close, many people get up and leave the building; others use different methods such as turning their back on the intruder. Living in cities has made people develop new skills for dealing with situations where they are very close to strangers. Most people on crowded trains try not to look at strangers; they avoid skin contact, and apologize if hands touch by mistake. People use newspapers (28)______ a barrier between themselves and other people, and if they do not have one, they stare into the distance, making sure they are not looking into anyone’s eyes.  

Question 24:

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word or phrase thet best fits each of the numbered blanks from 24 to 28:

 Personal space is a term that refers (24)______the distance we like to keep between ourselves  and other people. When (25)______we do not know well gets too close we usually begin to feel uncomfortable. If a business colleague comes closer than 1.2 meters, the most common response is to move (26_______ . Some interesting (27)______ have been done in libraries. If strangers come too close, many people get up and leave the building; others use different methods such as turning their back on the intruder. Living in cities has made people develop new skills for dealing with situations where they are very close to strangers. Most people on crowded trains try not to look at strangers; they avoid skin contact, and apologize if hands touch by mistake. People use newspapers (28)______ a barrier between themselves and other people, and if they do not have one, they stare into the distance, making sure they are not looking into anyone’s eyes.  

Question 27:

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word or phrase thet best fits each of the numbered blanks from 24 to 28:

 Personal space is a term that refers (24)______the distance we like to keep between ourselves  and other people. When (25)______we do not know well gets too close we usually begin to feel uncomfortable. If a business colleague comes closer than 1.2 meters, the most common response is to move (26_______ . Some interesting (27)______ have been done in libraries. If strangers come too close, many people get up and leave the building; others use different methods such as turning their back on the intruder. Living in cities has made people develop new skills for dealing with situations where they are very close to strangers. Most people on crowded trains try not to look at strangers; they avoid skin contact, and apologize if hands touch by mistake. People use newspapers (28)______ a barrier between themselves and other people, and if they do not have one, they stare into the distance, making sure they are not looking into anyone’s eyes.  

Question 28:

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word or phrase thet best fits each of the numbered blanks from 24 to 28:

 According to the European Pizza-Makers’ Association, making a good pizza is not a straight forward skill to learn. The ingredients seem very (24) _______: flour, yeast, water and a bit of salt. But water and flour can easily make glue and anyone who has eaten a (25) _______ quality pizza will know how bad it can make your stomach feel. “In Italy, 70% of pizza makers could improve on their product, not to (26) _______ all the pizza makers around the world who serve uneatable meals”, says Antonio Primiceri, the Association's founder. He has now started a pizza school in an attempt to save the reputation of this traditional dish. As part of a/ an (27) _______ course, the students at Mr Primiceri's school are taught to avoid common mistakes, produce a good basic mixture, add a tasty topping and cook the pizza properly. Test the finished pizza by breaking the crust, advises Mr Primiceri: “If the soft part inside the pizza is white, clean and dry, it's a good pizza. If it is not like this, the pizza will upset your stomach. You will feel (28) _______ full and also thirsty”. In Italy alone, the pizza industry has an annual turnover of more than $12 billion. Mr Primiceri estimated that there are 10,000 jobs in pizza restaurants waiting to be filled by those with real skills. “If you are a good pizza cook, you will never be without a job”, he says.

Question 24:       

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word or phrase thet best fits each of the numbered blanks from 24 to 28:

 According to the European Pizza-Makers’ Association, making a good pizza is not a straight forward skill to learn. The ingredients seem very (24) _______: flour, yeast, water and a bit of salt. But water and flour can easily make glue and anyone who has eaten a (25) _______ quality pizza will know how bad it can make your stomach feel. “In Italy, 70% of pizza makers could improve on their product, not to (26) _______ all the pizza makers around the world who serve uneatable meals”, says Antonio Primiceri, the Association's founder. He has now started a pizza school in an attempt to save the reputation of this traditional dish. As part of a/ an (27) _______ course, the students at Mr Primiceri's school are taught to avoid common mistakes, produce a good basic mixture, add a tasty topping and cook the pizza properly. Test the finished pizza by breaking the crust, advises Mr Primiceri: “If the soft part inside the pizza is white, clean and dry, it's a good pizza. If it is not like this, the pizza will upset your stomach. You will feel (28) _______ full and also thirsty”. In Italy alone, the pizza industry has an annual turnover of more than $12 billion. Mr Primiceri estimated that there are 10,000 jobs in pizza restaurants waiting to be filled by those with real skills. “If you are a good pizza cook, you will never be without a job”, he says.

Question 26:        

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word or phrase thet best fits each of the numbered blanks from 24 to 28:

 According to the European Pizza-Makers’ Association, making a good pizza is not a straight forward skill to learn. The ingredients seem very (24) _______: flour, yeast, water and a bit of salt. But water and flour can easily make glue and anyone who has eaten a (25) _______ quality pizza will know how bad it can make your stomach feel. “In Italy, 70% of pizza makers could improve on their product, not to (26) _______ all the pizza makers around the world who serve uneatable meals”, says Antonio Primiceri, the Association's founder. He has now started a pizza school in an attempt to save the reputation of this traditional dish. As part of a/ an (27) _______ course, the students at Mr Primiceri's school are taught to avoid common mistakes, produce a good basic mixture, add a tasty topping and cook the pizza properly. Test the finished pizza by breaking the crust, advises Mr Primiceri: “If the soft part inside the pizza is white, clean and dry, it's a good pizza. If it is not like this, the pizza will upset your stomach. You will feel (28) _______ full and also thirsty”. In Italy alone, the pizza industry has an annual turnover of more than $12 billion. Mr Primiceri estimated that there are 10,000 jobs in pizza restaurants waiting to be filled by those with real skills. “If you are a good pizza cook, you will never be without a job”, he says.

Question 25:       

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word or phrase thet best fits each of the numbered blanks from 24 to 28:

 According to the European Pizza-Makers’ Association, making a good pizza is not a straight forward skill to learn. The ingredients seem very (24) _______: flour, yeast, water and a bit of salt. But water and flour can easily make glue and anyone who has eaten a (25) _______ quality pizza will know how bad it can make your stomach feel. “In Italy, 70% of pizza makers could improve on their product, not to (26) _______ all the pizza makers around the world who serve uneatable meals”, says Antonio Primiceri, the Association's founder. He has now started a pizza school in an attempt to save the reputation of this traditional dish. As part of a/ an (27) _______ course, the students at Mr Primiceri's school are taught to avoid common mistakes, produce a good basic mixture, add a tasty topping and cook the pizza properly. Test the finished pizza by breaking the crust, advises Mr Primiceri: “If the soft part inside the pizza is white, clean and dry, it's a good pizza. If it is not like this, the pizza will upset your stomach. You will feel (28) _______ full and also thirsty”. In Italy alone, the pizza industry has an annual turnover of more than $12 billion. Mr Primiceri estimated that there are 10,000 jobs in pizza restaurants waiting to be filled by those with real skills. “If you are a good pizza cook, you will never be without a job”, he says.

Question 28:        

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word or phrase thet best fits each of the numbered blanks from 24 to 28:

 According to the European Pizza-Makers’ Association, making a good pizza is not a straight forward skill to learn. The ingredients seem very (24) _______: flour, yeast, water and a bit of salt. But water and flour can easily make glue and anyone who has eaten a (25) _______ quality pizza will know how bad it can make your stomach feel. “In Italy, 70% of pizza makers could improve on their product, not to (26) _______ all the pizza makers around the world who serve uneatable meals”, says Antonio Primiceri, the Association's founder. He has now started a pizza school in an attempt to save the reputation of this traditional dish. As part of a/ an (27) _______ course, the students at Mr Primiceri's school are taught to avoid common mistakes, produce a good basic mixture, add a tasty topping and cook the pizza properly. Test the finished pizza by breaking the crust, advises Mr Primiceri: “If the soft part inside the pizza is white, clean and dry, it's a good pizza. If it is not like this, the pizza will upset your stomach. You will feel (28) _______ full and also thirsty”. In Italy alone, the pizza industry has an annual turnover of more than $12 billion. Mr Primiceri estimated that there are 10,000 jobs in pizza restaurants waiting to be filled by those with real skills. “If you are a good pizza cook, you will never be without a job”, he says.

Question 27:      

Read the following pasage 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:

Our classes take place for three hours every morning from Monday to Friday. The (31)_________ class size is twelve and the average is ten. We use modern methods (32)_________ teaching  and learning, and the school has a language laboratory, a video camera and recorders. You will only be successful in improving your English; however, if you work hard and practise speaking English as much as you can. You will take a short (33)_________ in English as soon as you arrive. In this way, we can put you in a (34)_________ at the most suitable level. The emphasis is on oral communication practice in a wide (35)_________ of situations at the advanced knowledge. You will learn how to use language correctly and appropriately when you talk to native speakers. In addition, you will develop such study skills as reading efficiently, writing articles and reports, and note-taking from books and lectures.  

Question 34: