Trường hợp nào khi nhiệt phân tạo ra sản phẩm gồm oxit kim loại, nitơ đioxit và oxi?

Viết các phương trình phản ứng hóa học hoàn thành sơ đồ phản ứng sau (ghi rõ điều kiện nếu có)    

Cho dung dịch AgNO₃ tác dụng với dung dịch chứa chất X thấy tạo thành kết tủa T màu vàng. Cho kết tủa T tác dụng với dung dịch HNO₃ loãng dư thấy kết tủa tan. Chất X là:

Cho 13,5 gam Al tác dụng vừa đủ với 2,0 lít dung dịch thu được hỗn hợp khí A gồm NO và có tỉ khối với hidro là 14,75. Tính thể tích mỗi khí sinh ra (đktc)?  

Khí X là oxit của nitơ. Ở điều kiện thường, X có màu nâu đỏ. Công thức của X là:

Hòa tan hoàn toàn 1,2 gam kim loại X vào dung dịch dư thu được 0,224 lít khí ở đktc (sản phẩm khử duy nhất). Kim loại X là:

Hòa tan hoàn toàn 3,04 gam hỗn hợp X gồm (Fe,Cu) tác dụng hoàn toàn với dung dịch loãng dư, sau phản ứng thu được 0,896 lít khí NO (sản phẩm khử duy nhất, ở đktc). Tính khối lượng mỗi kim loại trong hỗn hợp X?

Tính chất hóa học cơ bản của NH₃ là:

        Viết phương trình hóa học theo sơ đồ sau, ghi rõ điều kiện (nếu có):    

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.

People used to know more or less how their children would live. Now things are changing so quickly that they don’t even know what their own lives will be like in a few years’ time. What follows is not science fiction. It is how experts see the future. You are daydreaming behind the steering wheel; is it too dangerous? No! That’s no problem because you have it on automatic pilot, and with its hi–tech computers and cameras, your car “know” how to get you home safe and sound. What is for lunch? In the old days you used to stop off to buy a hamburger or a pizza. Now you use your diagnostic machine to find out which foods your body needs. If your body needs more vegetables and less fat, your food–preparation machine makes you a salad. After lunch, you go down the hall to your home office. Here you have everything you need to do your work. Thanks to your information screen and your latest generation computer, you needn’t go to the office anymore. The information screen shows an urgent message from a co-worker in Brazil. You can instantly send back a reply to him and go on to deal with other matters.

Question: What is the main idea of the passage?          

Một túi có viên bi gồm viên bi màu trắng được đánh số từ đến ; viên bi màu đỏ được đánh số từ đến ; viên bi màu xanh được đánh số từ đến và viên màu vàng được đánh số từ đến . Có bao nhiêu cách chọn viên bi từng đôi khác số?  

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:

Studies about how students use their time might shed light on whether they face increased academic and financial pressures compared with earlier eras. Based on data about how students are spending time, academic or financial pressures don’t seem to be greater now than a generation ago. The data show that full-time students in all types of colleges study much less now than they did a generation ago–a full 10 hours a week less. Students are also receiving significantly higher grades. So it appears that academic pressures are, in fact, considerably lower than they used to be. The time–use data don’t suggest that students feel greater financial pressures, either. When the time savings and lower opportunity costs are factored in, college appears less expensive for most students than it was in the 1960s. and though there are now full-time students working to pay while in college, they study less even when paid work choices are held constantly. In other words, full-time students do not appear to be studying less in order to work more. They appear to be studying less and spending the extra time on leisure activities or fun. It seems hard to imagine that students feeling increased financial pressures would respond by taking more leisure. Based on how students are spending their time then, it doesn’t look as though academic or financial pressures are greater now than a generation ago. The time-use data don’t speak directly to social pressures, and it may well be that these have become more intense lately. In one recent set of data, students reported spending more than 23 hours per week either socializing with friends or playing on the computer for fun. Social activities, in person or on computer would seem to have become the major focus of campus life. It is hard to tell what kinds of pressures would be associated with this change.  

Question: The author finds it hard to point out__________         

Trong khai triển , hệ số của là:

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:

Studies about how students use their time might shed light on whether they face increased academic and financial pressures compared with earlier eras. Based on data about how students are spending time, academic or financial pressures don’t seem to be greater now than a generation ago. The data show that full-time students in all types of colleges study much less now than they did a generation ago–a full 10 hours a week less. Students are also receiving significantly higher grades. So it appears that academic pressures are, in fact, considerably lower than they used to be. The time–use data don’t suggest that students feel greater financial pressures, either. When the time savings and lower opportunity costs are factored in, college appears less expensive for most students than it was in the 1960s. and though there are now full-time students working to pay while in college, they study less even when paid work choices are held constantly. In other words, full-time students do not appear to be studying less in order to work more. They appear to be studying less and spending the extra time on leisure activities or fun. It seems hard to imagine that students feeling increased financial pressures would respond by taking more leisure. Based on how students are spending their time then, it doesn’t look as though academic or financial pressures are greater now than a generation ago. The time-use data don’t speak directly to social pressures, and it may well be that these have become more intense lately. In one recent set of data, students reported spending more than 23 hours per week either socializing with friends or playing on the computer for fun. Social activities, in person or on computer would seem to have become the major focus of campus life. It is hard to tell what kinds of pressures would be associated with this change.  

Question: The word “focus” in the last paragraph can be replaced with_______         

Biết hệ số của trong khai triển biểu thức là . Số nguyên bằng bao nhiêu?  

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:

Studies about how students use their time might shed light on whether they face increased academic and financial pressures compared with earlier eras. Based on data about how students are spending time, academic or financial pressures don’t seem to be greater now than a generation ago. The data show that full-time students in all types of colleges study much less now than they did a generation ago–a full 10 hours a week less. Students are also receiving significantly higher grades. So it appears that academic pressures are, in fact, considerably lower than they used to be. The time–use data don’t suggest that students feel greater financial pressures, either. When the time savings and lower opportunity costs are factored in, college appears less expensive for most students than it was in the 1960s. and though there are now full-time students working to pay while in college, they study less even when paid work choices are held constantly. In other words, full-time students do not appear to be studying less in order to work more. They appear to be studying less and spending the extra time on leisure activities or fun. It seems hard to imagine that students feeling increased financial pressures would respond by taking more leisure. Based on how students are spending their time then, it doesn’t look as though academic or financial pressures are greater now than a generation ago. The time-use data don’t speak directly to social pressures, and it may well be that these have become more intense lately. In one recent set of data, students reported spending more than 23 hours per week either socializing with friends or playing on the computer for fun. Social activities, in person or on computer would seem to have become the major focus of campus life. It is hard to tell what kinds of pressures would be associated with this change.  

Question: All factors considered, college now seems__________         

Khai triển đa thức ta được   Mệnh đề nào sau đây là đúng?          

 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:

Studies about how students use their time might shed light on whether they face increased academic and financial pressures compared with earlier eras. Based on data about how students are spending time, academic or financial pressures don’t seem to be greater now than a generation ago. The data show that full-time students in all types of colleges study much less now than they did a generation ago–a full 10 hours a week less. Students are also receiving significantly higher grades. So it appears that academic pressures are, in fact, considerably lower than they used to be. The time–use data don’t suggest that students feel greater financial pressures, either. When the time savings and lower opportunity costs are factored in, college appears less expensive for most students than it was in the 1960s. and though there are now full-time students working to pay while in college, they study less even when paid work choices are held constantly. In other words, full-time students do not appear to be studying less in order to work more. They appear to be studying less and spending the extra time on leisure activities or fun. It seems hard to imagine that students feeling increased financial pressures would respond by taking more leisure. Based on how students are spending their time then, it doesn’t look as though academic or financial pressures are greater now than a generation ago. The time-use data don’t speak directly to social pressures, and it may well be that these have become more intense lately. In one recent set of data, students reported spending more than 23 hours per week either socializing with friends or playing on the computer for fun. Social activities, in person or on computer would seem to have become the major focus of campus life. It is hard to tell what kinds of pressures would be associated with this change.  

Question: The word “Academics” in the title mostly means_________         

Tìm hệ số của trong khai triển