【Test Your Knowledge】Basic Chemical Engineering Knowledge (21)
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Change the scoring method: give higher scores for good answers, do not score random replies that lack thought, and deduct points for meaningless posts. Please cooperate, thank you. 1. Containers a, b, and c, all of which have open tops, contain the same liquid to the same height. If the areas of their bottoms are in the ratio Sa:Sb:Sc = 1:2:3, then the relationship between the static pressures at the bottoms of these three containers is: _______. A. Pa=2Pb=3Pc B. Pa=Pb=Pc C. Pa;Pc 2. The purpose of reducing the thermal resistance of the scale layer is ________. A. Increase the heat transfer area B. Decrease the heat transfer area C. Increase the heat transfer coefficient D. Increase the temperature difference 3. When benzene and toluene form an ideal solution, the mass fraction of benzene is 0.4; what is its molar fraction? A.0.5 B.0.54 C.0.45 D.0.6 4. According to Henry’s law, when gas and liquid are in equilibrium, the concentration of the component that can be absorbed in the liquid phase is in ________ relationship with its equilibrium partial pressure in the gas phase. A. Direct proportion B. Inverse proportion C. Proportional to the square D. Inverse proportional to the square 5. The unit operation of distillation belongs to the ________ process. A. Unidirectional mass transfer B. Bidirectional mass transfer C. Heat transfer D. Molecular transfer 6. The value of the reflux ratio plays an important role in the design of the number of plates in a distillation column and the location of the feed. （ ） 7. The boiling range is also known as the distillation range. It refers to the temperature range of a single-component hydrocarbon from its initial boiling point to its dry point under certain pressure. （ ） 8. In a stationary liquid, the pressure at any point within the liquid depends only on the density of the fluid, and not on the depth of the liquid. （ ） 9. For a given mass of gas, at constant pressure, its volume is inversely proportional to its thermodynamic temperature (or absolute temperature). （ ） 10. When molecular sieves are used as adsorbents, selective adsorption can be achieved based on the degree of unsaturation of the molecules; the greater the degree of unsaturation, the more molecules will be adsorbed. ( ) Answer key: 5th floor is correct. This post was last edited by zhangyong6404 on 2009-4-4 16:27.]
1、A； 2、C ； 3、C ； 4. A (or C?) Hehe, I’ve forgotten a lot of formulas.) ； 5、B ； 6、Y ； 7、N ； 8、N ； 9、N ； 10. Y (Should I say that?) It seems a bit complicated; it’s probably related to the size of the molecules as well. Well…………the magnitude of this force might not necessarily indicate much, right? ? ）
1 A 2 C 3 A 4 A 5 A
1. Containers a, b, and c, all of which have open tops, contain the same liquid to the same height. If the areas of their bottoms are in the ratio Sa:Sb:Sc = 1:2:3, then the relationship between the static pressures at the bottoms of these three containers is: ____B___. (Analysis: If the heights are the same, the pressure is the same.) A. Pa=2Pb=3Pc B. Pa=Pb=Pc C. Pa×Pc 2. The purpose of reducing the thermal resistance of the scale layer is __C______. (Analysis: The fouling layer contributes to the total heat transfer resistance.) A. Increase the heat transfer area B. Decrease the heat transfer area C. Increase the heat transfer coefficient D. Increase the temperature difference. 3. When benzene and toluene form an ideal solution, the mass fraction of benzene is 0.4; its molar fraction is __C______. A.0.5 B.0.54 C.0.45 D.0.6 4. According to Henry’s law, when gas and liquid are in equilibrium, the concentration of the component that can be absorbed in the liquid phase is ___A_____ to its equilibrium partial pressure in the gas phase. (p*=Ex) A. Direct proportion B. Inverse proportion C. Proportional to the square D. Inverse proportional to the square 5. The unit operation of distillation belongs to the ___B_____ process. A. Unidirectional mass transfer B. Bidirectional mass transfer C. Heat transfer D. Molecular transfer 6. The value of the reflux ratio plays an important role in the design of the number of plates in a distillation column and the location of the feed. (T) 7. Boiling range is also known as distillation range. It refers to the temperature range of a single-component hydrocarbon from its initial boiling point to its dry point under certain pressure. (F) 8. In a stationary liquid, the pressure at any point within the liquid depends only on the density of the fluid, and not on the depth of the liquid. (F) 9. For a fixed mass of gas, at constant pressure, its volume is inversely proportional to its thermodynamic temperature (or absolute temperature). (F) 10. When molecular sieves are used as adsorbents, selective adsorption can be achieved based on the degree of unsaturation of the molecules; the greater the degree of unsaturation, the more substances will be adsorbed. (F)
1 B 2 C 3 C 4 A 5 B 6 √ 7 X 8 X 9 X 10 √
1. Containers a, b, and c, all of which have open tops, contain the same liquid to the same height. If the areas of their bottoms are in the ratio Sa:Sb:Sc = 1:2:3, then the relationship between the static pressures at the bottoms of these three containers is: ___B____. A. Pa=2Pb=3Pc B. Pa=Pb=Pc C. Pa×Pc 2. The purpose of reducing the thermal resistance of the scale layer is ____C____. A. Increase the heat transfer area B. Decrease the heat transfer area C. Increase the heat transfer coefficient D. Increase the temperature difference. 3. When benzene and toluene form an ideal solution, the mass fraction of benzene is 0.4; its molar fraction is ___C_____. A.0.5 B.0.54 C.0.45 D.0.6 4. According to Henry’s law, when gas and liquid are in equilibrium, the concentration of the component that can be absorbed in the liquid phase is in ____A____ relationship with its equilibrium partial pressure in the gas phase. A. Direct proportion B. Inverse proportion C. Proportional to the square D. Inverse proportional to the square 5. The unit operation of distillation belongs to ___B, C_____ processes. A. Unidirectional mass transfer B. Bidirectional mass transfer C. Heat transfer D. Molecular transfer 6. The value of the reflux ratio plays an important role in the design of the number of plates in a distillation column and the location of the feed. (Yes) 7. The boiling range is also known as the distillation range. It refers to the temperature range of a single-component hydrocarbon from its initial boiling point to its dry point under certain pressure. (Incorrect) 8. In a stationary liquid, the pressure at any point within the liquid depends only on the density of the fluid, and not on the depth of the liquid. (Incorrect) 9. For a fixed mass of gas, at constant pressure, its volume is inversely proportional to its thermodynamic temperature (or absolute temperature). (Incorrect) 10. When molecular sieves are used as adsorbents, selective adsorption can be achieved based on the degree of unsaturation of the molecules; the greater the degree of unsaturation, the more molecules will be adsorbed. (Wrong)
1. Containers a, b, and c, all of which have open tops, contain the same liquid to the same height. If the areas of their bottoms are in the ratio Sa:Sb:Sc = 1:2:3, then the relationship between the static pressures at the bottoms of these three containers is: ____B___. A. Pa=2Pb=3Pc B. Pa=Pb=Pc C. Pa×Pc 2. The purpose of reducing the thermal resistance of the scale layer is _____C___ . A. Increase the heat transfer area B. Decrease the heat transfer area C. Increase the heat transfer coefficient D. Increase the temperature difference. 3. When benzene and toluene form an ideal solution, the mass fraction of benzene is 0.4; its molar fraction is ____C____. A.0.5 B.0.54 C.0.45 D.0.6 4. According to Henry’s law, when gas and liquid are in equilibrium, the concentration of the component that can be absorbed in the liquid phase is in ____A____ relationship with its equilibrium partial pressure in the gas phase. A. Direct proportion B. Inverse proportion C. Proportional to the square D. Inverse proportional to the square 5. The unit operation of distillation belongs to a ____C____ process. A. Unidirectional mass transfer B. Bidirectional mass transfer C. Heat transfer D. Molecular transfer 6. The value of the reflux ratio plays an important role in the design of the number of plates in a distillation column and the location of the feed. (Yes) 7. The boiling range is also known as the distillation range. It refers to the temperature range of a single-component hydrocarbon from its initial boiling point to its dry point under certain pressure. （ ） 8. In a stationary liquid, the pressure at any point within the liquid depends only on the density of the fluid, and not on the depth of the liquid. (Incorrect) 9. For a fixed mass of gas, at constant pressure, its volume is inversely proportional to its thermodynamic temperature (or absolute temperature). (Incorrect) 10. When molecular sieves are used as adsorbents, selective adsorption can be achieved based on the degree of unsaturation of the molecules; the greater the degree of unsaturation, the more molecules will be adsorbed. (Yes)
1. B (According to the equations of statics, the pressure at any point in a stationary fluid is related to the density of the liquid and its depth. P2 = p0 + ρgh). 2. C: By reducing the thermal resistance of the scale layer, the overall thermal resistance for heat transfer is reduced, thereby increasing the heat transfer rate. Process rate = Driving force of the process / Resistance to the process). 3. C (Calculation formula: (0.4/78) / (0.4/78 + 0.6/92)). 4. A (Henry’s law expression: p* = Ex). 5. B (From gas to liquid, from liquid to gas). 6. √. 7. × (Boiling range is also known as distillation range). It refers to the temperature range of mixed hydrocarbon components from the initial boiling point to the dry point under certain pressure. ) 8、× (According to the equations of statics, the pressure at any point within a stationary fluid is related to the density of the liquid and its depth. ) 9、× (Based on the ideal gas law: pV=nRT. For a given mass of gas, at constant pressure, its volume is proportional to its thermodynamic temperature (or absolute temperature). ) 10, × (Factors affecting adsorption capacity: 1. Temperature: The adsorption capacity decreases as temperature rises. 2. Flow rate: The higher the flow rate, the worse the adsorption effect. 3. Degree of regeneration perfection: The more thorough the regeneration desorption, the greater the adsorption capacity. 4. Molecular sieve thickness: A thicker adsorbent layer provides better adsorption performance. ）
1、B 2、C 3、C 4、A 5、B 6、Correct 7、Incorrect (it is not a single-component hydrocarbon) 8、Incorrect (it depends on both density and depth) 9、Incorrect (it is proportional) 10、Correct
1. Containers a, b, and c, all of which have open tops, contain the same liquid to the same height. If the areas of their bottoms are in the ratio Sa:Sb:Sc = 1:2:3, then the relationship between the static pressures at the bottoms of these three containers is: _____B__. A. Pa=2Pb=3Pc B. Pa=Pb=Pc C. Pa;Pc 2. The purpose of reducing the thermal resistance of the scale layer is __C_______. A. Increase the heat transfer area B. Decrease the heat transfer area C. Increase the heat transfer coefficient D. Increase the temperature difference. 3. When benzene and toluene form an ideal solution, the mass fraction of benzene is 0.4; its molar fraction is ___C_____. A.0.5 B.0.54 C.0.45 D.0.6 4. According to Henry’s law, when gas and liquid are in equilibrium, the concentration of the component that can be absorbed in the liquid phase is directly proportional to its equilibrium partial pressure in the gas phase___B______. A. Direct proportion B. Inverse proportion C. Proportional to the square D. Inverse proportional to the square 5. The unit operation of distillation belongs to a _____A___ process. A. Unidirectional mass transfer B. Bidirectional mass transfer C. Heat transfer D. Molecular transfer 6. The value of the reflux ratio plays an important role in the design of the number of plates in a distillation column and the location of the feed. ( √ ) 7. The boiling range is also known as the distillation range. It refers to the temperature range of a single-component hydrocarbon from its initial boiling point to its dry point under certain pressure. ( × ) 8. In a stationary liquid, the pressure at any point within the liquid depends only on the density of the fluid, and not on the depth of the liquid. ( ×) 9. For a fixed mass of gas, at constant pressure, its volume is inversely proportional to its thermodynamic temperature (or absolute temperature). (×) 10. When molecular sieves are used as adsorbents, selective adsorption can be achieved based on the degree of unsaturation of the molecules; the greater the degree of unsaturation, the more molecules will be adsorbed. ( √ ) This post was last edited by liuwenqiu on 2009-4-3 17:22 ]
1、B 2、C 3、C 4、A 5、B 6、√ 7、× 8、× 9、× 10、√
1. B. Pa=Pb=Pc 2. C. Increase the heat transfer coefficient 3. C. 0.45 4. A. Proportional 5. B. Two-way mass transfer 6. (√) 7. (×) 8. (×) 9. (×) 10. (√)
1.B 2.C 3.C 4.A 5.B 6.√ 7.X 8.X 9.X 10.√
1. Containers a, b, and c, all of which have open tops, contain the same liquid to the same height. If the areas of their bottoms are in the ratio Sa:Sb:Sc = 1:2:3, then the relationship between the static pressures at the bottoms of these three containers is: ___B____. 2. The purpose of reducing the thermal resistance of the scale layer is ___C______. A. Increase the heat transfer area B. Decrease the heat transfer area C. Increase the heat transfer coefficient D. Increase the temperature difference. 3. When benzene and toluene form an ideal solution, the mass fraction of benzene is 0.4; its molar fraction is ___C_____. A.0.5 B.0.54 C.0.45 D.0.6 4. According to Henry’s law, when gas and liquid are in equilibrium, the concentration of the component that can be absorbed in the liquid phase is ___A_____ to its equilibrium partial pressure in the gas phase. A. Direct proportion B. Inverse proportion C. Proportional to the square D. Inverse proportional to the square 5. The unit operation of distillation belongs to the __B______ process. A. Unidirectional mass transfer B. Bidirectional mass transfer C. Heat transfer D. Molecular transfer 6. The value of the reflux ratio plays an important role in the design of the number of plates in a distillation column and the location of the feed. ( True ) 7. The boiling range is also known as the distillation range. It refers to the temperature range of a single-component hydrocarbon from its initial boiling point to its dry point under certain pressure. (Incorrect) 8. In a stationary liquid, the pressure at any point within the liquid depends only on the density of the fluid, and not on the depth of the liquid. (Incorrect) 9. For a fixed mass of gas, at constant pressure, its volume is inversely proportional to its thermodynamic temperature (or absolute temperature). (Yes) 10. When molecular sieves are used as adsorbents, selective adsorption can be achieved based on the degree of unsaturation of the molecules; the greater the degree of unsaturation, the more substances will be adsorbed. (Yes :) ) This post was last edited by lujianfei79 on 2009-4-3 18:28 ]
1.B 2.C 3.C 4.A 5.B 6.√ 7.X 8.X 9.X 10.X
1、B. 2、B. 3、C 4、A. 5、C. 6、Correct 7、Incorrect 8、Incorrect 9、Incorrect 10、Incorrect Last edited by yzq2213 on 2009-4-3 19:29]
Answer: 1 B 2 C 3 C 4 A 5 B 6 √ 7 X 8 X 9 X 10 √
1. Containers a, b, and c, all of which have open tops, contain the same liquid to the same height. If the areas of their bottoms are in the ratio Sa:Sb:Sc = 1:2:3, then the relationship between the static pressures at the bottoms of these three containers is: ____B___. A. Pa=2Pb=3Pc B. Pa=Pb=Pc C. Pa×Pc 2. The purpose of reducing the thermal resistance of the scale layer is _____C___ . A. Increase the heat transfer area B. Decrease the heat transfer area C. Increase the heat transfer coefficient D. Increase the temperature difference. 3. When benzene and toluene form an ideal solution, the mass fraction of benzene is 0.4; its molar fraction is _____C___. A.0.5 B.0.54 C.0.45 D.0.6 4. According to Henry’s law, when gas and liquid are in equilibrium, the concentration of the component that can be absorbed in the liquid phase is in ____A____ relationship with its equilibrium partial pressure in the gas phase. A. Direct proportion B. Inverse proportion C. Proportional to the square D. Inverse proportional to the square 5. The unit operation of distillation belongs to a ______B__ process. A. Unidirectional mass transfer B. Bidirectional mass transfer C. Heat transfer D. Molecular transfer 6. The value of the reflux ratio plays an important role in the design of the number of plates in a distillation column and the location of the feed. (R) 7. Boiling range is also known as distillation range. It refers to the temperature range of a single-component hydrocarbon from its initial boiling point to its dry point under certain pressure. (F) 8. In a stationary liquid, the pressure at any point within the liquid depends only on the density of the fluid, and not on the depth of the liquid. (F) 9. For a given mass of gas, at constant pressure, its volume is inversely proportional to its thermodynamic temperature (or absolute temperature). (F) 10. When molecular sieves are used as adsorbents, selective adsorption can be achieved based on the degree of unsaturation of the molecules; the greater the degree of unsaturation, the more substances will be adsorbed. (R)
1、A； 2、C ； 3、C ； 4, A 5, B ； 6、√ ； 7、X ； 8、X ； 9、X ； 10、√
B C C A B √ X X X √
1. B is determined according to the White equation. 2. C: Reducing the thermal resistance can improve heat transfer efficiency, that is, it can increase the heat transfer coefficient. 3. C needs to be calculated; it’s quite simple. 4. Herry’s law 5. B In the distillation process, mass transfer between the gas and liquid phases occurs such that the heavier components in the gas phase are transferred to the liquid phase, while the lighter components in the liquid phase are transferred to the gas phase, thereby achieving separation. 6. True 7. F It is not a single-component system. 8. F White’s equation 9. F Gas state equation 10. F