Số đồng phân amin bậc 2 có công thức phân tử C4H11N là:         

Chia sẻ

Một số câu hỏi khác có thể bạn quan tâm.

• Phương trình chỉ có các nghiệm là:                         

• – “What_______ beautiful dress you are wearing!”-“ Thank you. That is _______ nice compliment. ”

• Hấp thụ hết V lít CO2 (ở đktc) vào 100 ml dung dịch gồm NaOH 2,0M và Na₂CO₃ 1,0M thu được dung dịch X. Chia X thành 2 phần bằng nhau:

  - Phần 1 cho tác dụng với CaCl₂ dư thu được b mol kết tủa.

  - Phần 2 cho tác dụng với nước vôi trong dư thu được c mol kết tủa. Biết 3b = c. Giá trị của V là ?  

• Read the passage carefully and choose the correct answers
  Marriage nowadays is a choice people make on their own, but this has not always been the case in society. Thousands of years ago, the average lifespan was shorter than it is today. A man usually lived until he was about 40 years old, while women died even sooner because of childbirth. There were many wars and illnesses, and people had to protect themselves by having more children while they were still young. The parents lived through their children.
  Marriage was not so much a romantic love story but a business transaction, or deal. Most marriages were arranged between parents while their children were still very young. It was the custom that the fathers made the decision on whom their children were going to marry. The mothers had little say in it since they rarely made any decisions outside the household. The fathers would meet to arrange the wedding date and the money given for the bride on her wedding date. The more money and land a girl had, the more chances she had to marry well. Therefore, it was important that her father choose the bridegroom very well. Usually, it was someone who came from a good family or who was rich too. It was very unlikely that people married outside their social class. A few well-off and rich merchants got to marry poorer noblewomen and became King’s business advisors. In a way, poor peasants had an easier choice as it was less important whom they married.
  The practice of arranged marriage is still common in some countries in the Middle East, such as India or Pakistan. Here, social classes are still strongly divided and very well-kept. Often, however, arranged marriages are a sign that people do not want to let go of the past, which gives them comfort and security in an ever-changing world.
  (Adapted from Longman Essence Reading, Vol. 2)
  Question. According to paragraph 1, women died even sooner than men because of ______.
  

• He insisted that he _______ really very tried and he _______to have a rest.

• Ý nào sau đây đúng với hoạt động ngoại thương của LB Nga?
  

• Cho hàm số có đồ thị như hình vẽ bên dưới. Đồ thị hàm số có tổng tung độ của các điểm cực trị bằng    

• Khái niệm dùng để chỉ những thuộc tính cơ bản vốn có của sự vật, hiện tượng, biểu thị trình độ phát triển, quy mô tốc độ vận động của sự vật, hiện tượng là

• Hai lò xo có khối lượng không đáng kể, độ cứng lần lượt là và, được mắc nối tiếp nhau. Độ cứng của hệ hai lò xo ghép trên là

• Từ một hộp chứa  quả cầu màu đỏ và  quả cầu màu xanh, lấy ngẫu nhiên đồng thời 3 quả cầu. Xác suất để lấy được  quả cầu màu xanh