Refining Knowledge (Technology) Daily Question (64) 11.28

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This post was last edited by chengkang on 2009-11-30 at 11:44. Everyone is welcome to actively participate in the learning and discussion of professional basic knowledge in the refinery processing technology exchange area! In accordance with the forum’s uniform requirements, the maximum score for this event is 10 Wealth points, and rating charm is prohibited. Friendships and duplicate ratings are also declined. Please be cautious when posting; edits will not be valid! Those who have different opinions on the provided answers can post discussions the next day, and those who provide solutions or their own opinions regarding the daily question will receive appropriate rewards! The focus is on participation, and there are prizes for it! To prevent some members from copying other members’ answers, please hide your posts when answering questions. For specific hiding methods, see: http://bbs.hcbbs.com/viewthread.php?tid=492556&highlight=%D2%FE%B2%D8 H9 Q8 x: O/ {9 e: F Note: Urgent call for contributors to provide a daily question on refining knowledge (technology). Thread address: http://bbs.hcbbs.com/thread-553526-1-1.html We look forward to active participation from those who are willing to answer the questions! I. Multiple-choice questions 1. To achieve the following changes, oxidants need to be added (　　). A. HCl→Cl2 B. NaCl→HCl C. HCl→H2 D. CaCO3→CO2 2. Among hydrocarbons from different groups, when their relative molecular weights are similar, the one with the greatest specific heat capacity is (　　). A. Alkanes B. Cycloalkanes C. Light aromatic hydrocarbons D. Heavy aromatic hydrocarbons 3. When water with a flow rate of 50 m3/h is transported using a seamless steel pipe with dimensions of φ108×4 mm, what is the flow velocity of the water inside the pipe? (　　) A、3.14 m/s B、1.77 m/s C、2.56 m/s D、5.08 m/s 4. Steps for putting into use a new material metering device with a bypass valve: First, open the bypass valve, and the fluid flows through the bypass pipe for a while first ； Slowly open the upstream valve ； Slow (　　) ； Slowly close the bypass valve. A. Open the upstream valve B. Close the upstream valve C. Open the downstream valve D. Close the downstream valve 5. Regarding the types of motors, which of the following statements are incorrect? (　　) A. Classified by the type of energy used, they can be divided into DC motors and AC motors. B. Classified by the voltage of the power supply, they can be divided into synchronous motors and asynchronous motors. C. Classified by the number of phases of the power supply, they can be divided into single-phase motors and three-phase motors. D. Based on whether they are used in environments with explosive gases, they can be divided into explosion-proof motors and non-explosion-proof motors. II. True or False Questions 1. As long as the temperature at the top of the initial distillation tower remains constant, the dry point of the gasoline obtained from that stage will not change. 2. If the properties of the crude oil become lighter, the amount drawn from the bottom of the distillation column should be reduced appropriately. 3. During wet vacuum distillation, steam must not be introduced at the bottom of the vacuum distillation column. 4. With the initial top temperature remaining constant, an increase in the initial top pressure will lead to a decrease in the yield of the initial top product. 5. Excessively high fuel oil pressure in the heating furnace can lead to black smoke or flame out when adjusting the temperature and flame. Answer: A A B C B Wrong Right Wrong Right Right