★Specialized Examination for Chemical Engineering ★ — One question per day (2015-11-16) — Points are awarded for participation
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This post was last edited by zshiwei2008 on 2015-11-17 08:14. To boost the activity in the Chemistry section, and in anticipation of that exam whose date is still unknown, at the suggestion of T Chao, a daily question activity is now being tried out in this section. Following the format of similar forums, 1-2 questions will be posted daily for candidates to discuss, and I will provide the answers the following day (which may also be subject to debate). Points system for the daily question: Participation – 1~3 points; Correct answer – 5 points; In-depth analysis – 5~10 points. To avoid interfering with others’ ability to answer, scores will be released in the afternoon of the same day. Starting with the unit operations in chemical engineering principles, the initial plan is to assign 2 questions per day: one multiple-choice question to make it easier for everyone to answer, and one basic analysis or calculation question. Daily Question (2015-11-16) 1. The “three types of transfer” in the principles of chemical engineering refer to: A. Transfer of kinetic energy, transfer of potential energy, transfer of chemical energy B. Transfer of kinetic energy, transfer of internal energy, transfer of mass C. Transfer of momentum, transfer of energy, transfer of heat D. Transfer of momentum, transfer of heat, transfer of mass 2. Given that the densities of sulfuric acid and water are 1830 kg/m3 and 998 kg/m3 respectively, what is the density of a sulfuric acid-water solution that is 60% by mass sulfuric acid? Answer key: Both of these questions are quite simple. The first question is similar to an actual exam question that has been asked before, while the second question relates to the basic knowledge of material balance. Answer to question 1: D. Momentum transfer, heat transfer, mass transfer. The answer analysis provided by f9kx on the fourth floor is quite detailed. Answer to question 2: 1/ρm = 0.6/1830 + 0.4/998 = (3.28 + 4.01)×10^-4 = 7.29×10^-4; therefore ρm = 1372 kg/m3
1/ρm = 0.6/1830 + 0.4/998 = 0.00033 + 0.0004 = 0.00073; ρm = 1/0.00073 = 1370 kg/m3
1. “Three types of transfer and one type of reaction” are fundamental concepts in chemical engineering: momentum transfer (fluid transport, filtration, sedimentation, etc.), heat transfer (heating, cooling, etc.), and mass transfer (evaporation, extraction, absorption, desorption, etc.). 2. The volume of sulfuric acid V1 = 0.6 m/1830; the volume of water V2 = 0.4 m/998； Total density ρ = m/(V1+V2) ； The answer is on the third floor ； The answer to this question can only be an approximate one, because the total volume is not equal to (V1+V2)
Select D: Momentum transfer, Heat transfer, Mass transfer
The “three transfers” in the principles of chemical engineering refer to: D 1370 kg/m3
1、 D 2、1372.36 Kg/M3
D Momentum transfer Heat transfer Mass transfer 1372.3
D 1372.4 kg/m3 – it’s written on the process floor. Give the original poster a thumbs up! Keep going definitely~~~
1. The “three transfers” in the principles of chemical engineering refer to: D Momentum transfer, Heat transfer, Mass transfer
Given that the densities of sulfuric acid and water are 1830 kg/m3 and 998 kg/m3 respectively, determine the density of a sulfuric acid aqueous solution containing 60% sulfuric acid by mass. 1372.36 Kg/M3