Hơp chất hữu cơ X có công thức phân tử C₂H₁₀N₄O₆. Cho 18,6 gam X tác dụng với 250 ml dung dịch NaOH 1M cho đến khi phản ứng xảy ra hoàn toàn thì thu được dung dịch Y. Cô cạn Y thu được hơi có chứa một chất hữu cơ duy nhất làm xanh giấy quỳ ẩm và đồng thời thu được a gam chất rắn. Giá trị a là 

A. 17 gam

B. 19 gam. 

C. 15 gam

D. 21 gam

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

A small but growing group of scholar, evolutionary, psychologists, are being to sketch the contours of the human mind as designed by natural selection. Some of them even anticipate the coming of a field called "mismatch theory", which would study maladies resulting from contrasts between the modern environment and the "ancestral environment". The one we were designed for.

There is no shortage of such maladies to study, Rates of depression have been doubling in some industrial countries roughly every 10 years. Suicide is the third most common cause of death among young adults, after car wrecks and homicides.

Evolutionary psychology is a long way from explaining all this with precision, but it is already shedding enough light to challenges some conventional wisdom. It suggests, for example, that the nostalgia for the nuclear family of the 1950s is in some way misguided - that the model family of husband at work and wife

at home is hardly a "natural" and healthful living arrangement, especially for the wives. Moreover, the bygone lifestyles that do look fairly natural in light of evolutionary psychology appear to have been eroded largely by commercialism. Perhaps the biggest surprise from evolutionary psychology it its depiction of the "animal" in us. Freud, and various thinkers since, saw "civilization" as an oppressive force that thwarts basic animal instincts and urges and transmutes them into psychopathology. However, evolutionary psychology suggests that a larger threat to metal health may be the way civilization thwarts civility. There is a gentler, kinder side of human nature, and it seems increasingly to be a victim of repression in modern society.

According to the passage, the death of many young people in industrial countries is mainly caused by

A. traffic accidents

B. murder

C. depression

D. suicide

Chất hữu cơ X mạch hở, không phân nhánh có công thức phân tử C₄H₈O₂. Cho X tác dụng với hiđro (xúc tác Ni, t⁰) thu được sản phẩm Y có khả năng hòa tan Cu(OH)₂. Số đồng phân cấu tạo bền của X thỏa mãn các điều kiện trên là

A. 4

B. 5

C. 3

D. 7

Số đồng phân là ancol thơm ứng với CTPT C₉H₁₂O là :

A. 17 

B. 18 

C. 19 

D. 20

Chất nào dưới đây khi cho vào dung dịch AgNO₃/NH₃ (t^o) , không xảy ra phản ứng tráng bạc

A. Saccarozơ.             

B. Glucozơ.            

C. Fructozơ.            

D. metylfomat.

Đun nóng hỗn hợp gồm glixerol, axit axetic và axit propionic với H₂SO₄ đặc, thu được tối đa k hợp chất hữu cơ chứa một chức este. Giá trị của k là

A. 1

B. 4

C. 3

D. 2

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.

After two decades of growing student enrollments and economic prosperity, business schools in the United States have started to face harder times. Only Harvard's MBA School has shown a substantial increase in enrollment in recent years. Both Princeton and Stanford have seen decreases in their enrollments. Since 1990, the number of people receiving Masters in Business Administration (MBA) degrees, has dropped about 3 percent to 75,000, and the trend of lower enrollment rates is expected to continue.

There are two factors causing this decrease in students seeking an MBA degree. The first one is that many graduates of four-year colleges are finding that an MBA degree does not guarantee a plush job on Wall Street, or in other financial districts of major American cities. Many of the entry-level management jobs are going to students graduating with Master of Arts degrees in English and the humanities as well as those holding MBA degrees. Students have asked the question, "Is an MBA degree really what I need to be best prepared for getting a good job?" The second major factor has been the cutting of American payrolls and the lower number of entry-level jobs being offered. Business needs are changing, and MBA schools are struggling to meet the new demands.

As used in paragraph 2, the word "seeking" could best be replaced by which of the following?

A. examining

B. avoiding

C. seizing

D. pursuing