One Question per Day (December 4th, 5th)
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This post was last edited by yanran88 on 2010-12-4 at 12:42. One question per day (December 4th, 5th); please hide your replies! 1. Among the following groups of substances, which ones represent the same substance? ( ) A. Water, ice, dry ice B. Blue vitriol, green vitriol, CuSO4 crystals C. Marble, quicklime, limestone D. Caustic soda, lye, NaOH 2. The speed at which steam rises inside a tower has a direct impact on the efficiency of mass transfer; the maximum allowable speed of steam rise in such a tower is ﹙﹚. A. Empty tower velocity B. Flood velocity C. 1/2 empty tower velocity D. Flood velocity 3. When a distillation column is changed from a plate column to a packed column, the ( ) of the column can be improved. A. Processing capacity B. Reboil ratio C. Top temperature of the tower D. Tower pressure 4. The smallest particle that retains the chemical properties of a substance is called ( ). A. Molecule B. Atom C. Proton D. Neutron 5. At constant pressure, the transformation of a substance from a liquid state to a gas state is called vaporization. Two ways of vaporization: ( ) and boiling. A. Evaporation B. Sublimation C. Stripping D. Reaction
1.D2.BD is less than the flooding velocity (the same for BD). 3.B4.A5.A
I hadn’t come into contact with chemical engineering knowledge for a long time since leaving school; I’ll try to answer: D, B, A, B, D. I’d like to know the correct answers.
I’m really sorry; I got the last question wrong.
Answer: I choose 1B, 2A, 3A, 4B, 5B
Reply to 1# yanran88: It’s recommended to provide the answers as well, so it’s easier to compare :)