【Test Your Knowledge】Basic Chemical Engineering Knowledge (254) Please hide your replies

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This post was last edited by zhangyong6404 on 2009-11-29 08:07. In accordance with the forum’s guidelines, the maximum score for this activity is 15 Wealth points; giving scores based on charm is prohibited. At the same time, friendship requests and repeated ratings are declined. To encourage active participation from members, full marks are given for all correct answers, while 10–12 wealth points are deducted for each incorrect answer. 2 mistakes result in 8–10 wealth points; the rest receive encouragement bonuses of 4–6 wealth points. Basic Chemistry Section (Multiple Choice Questions): 1. At a constant temperature, into a container with a volume of 2 dm3. The evacuated container is sequentially filled with gas A at an initial pressure of 100 kPa and a volume of 2 dm3, and gas B at a pressure of 200 kPa and a volume of 2 dm3. Both A and B can be treated as ideal gases, and no chemical reaction occurs between A and B. The total pressure of the gas mixture in the container is ( ). A、300kPa B、200kPa C、150kPa D、100kPa 2、Which of the following uses of substances is determined by the chemical properties of those substances? ( ) A. Using activated carbon to absorb colored substances. B. Using diamond as a drill bit. C. Filling balloons with hydrogen for advertising purposes. D. Using hydrochloric acid to remove rust. 3. Oxygen is a substance that is commonly found around us. Which of the following statements about oxygen is incorrect? ( ) A. Oxygen is flammable. B. Oxygen enables the respiration of plants and animals. C. Oxygen supports combustion. D. Some substances cannot burn in air but can burn in oxygen. 4. The chemical equations for the combustion of liquefied petroleum gas are: CH4+2O2==CO2+2H2O, C3H8+5O2==3CO2+4H2O. There is currently a set of stoves that use natural gas as fuel; to convert them to stoves that use liquefied petroleum gas as fuel, what measures should be taken? ( ) A. Both the amount of fuel gas and air entering decreases. B. Both the amount of fuel gas and air entering increases. C. Either the amount of fuel gas entering is reduced or the amount of air entering is increased. D. Either the amount of fuel gas entering is increased or the amount of air entering is reduced. 5. When Mg, Al, and Zn are placed in hydrochloric acid with the same mass fraction of solute, the masses of hydrogen gas produced after complete reaction are equal; what could be the reason for this? ( ) A. The masses of the three metals added are equal, and there is an adequate supply of hydrochloric acid. B. The mass ratio of Mg, Al, and Zn added is 12:18:32.5, with an adequate supply of hydrochloric acid. C. The amount of hydrochloric acid used is the same, and an adequate amount of each of the three metals is added. D. The mass ratio of hydrochloric acid used is 3:2:1, and no hydrochloric acid remains after the reaction. Chemical principles section (single-choice question): 6. Shortly after a centrifugal pump is started, the vacuum level at the pump’s inlet is normal, but the pressure gauge at the outlet gradually drops to zero; at this point, the centrifugal pump can no longer pump water out. The reason for the failure is ( ). A. Forgetting to water it B. Blockage in the suction pipeline C. Blockage in the discharge pipeline D. Air leakage in the suction pipeline 7. When a centrifugal pump is operating normally, what is the relationship between its head and the lift height? ( ) A. Head > lift height B. Head = lift height C. Head