七年级上册英语周报第14期。答案

第二节(满分25分)One possible versionThen came the Rajasthan /v trip which was our official last trip I hanged out with my otherErieiends while she with the other two girls. I wasn,t enjoying this trip at all, which she could makeBout. When she saw me approaching the common washroom, she followed me in and shut thedoor. I didn 't know how to react. She gave me a tight hug and broke down. My tears were alsoout of control We knew we both wanted to be in each others company. We promised to growmature and let it not affect our friendshipaozIt's been almost 7 years after graduation since we picked up our friendship. Shes one of thefew people I really count on in my life. She's been with me through all my struggles, helping meconstantly to grow into a better individual. So have I. The only learning from our relationshipis-if someone is meant to be in your life, they will ensure they stay around some way or theher Willingness to keep a relationship should come from both the sides

17.(1)H:C::C:H(2分)2)能耗低(或产物易分离,2分)(3)45(2分)(4)C2H(g)+CO2=C2H(g)+(O(g)+H2O(1)△H=+133.2kJ·mol-(2分);积碳能与CO2反应生成CO,从而脱离催化剂表面(2分)(5)氢气移出率增大,体系中氢气的浓度降低,平衡正向移动,乙烷的平衡转化率增大(2分);90%(2分)【解析】本题主要考查化学反应原理,考查学生对化学反应原理的理解能力和综合运用能力。HH(1)乙烯电子式为H:C::C:H(2)氧化裂解反应是放热反应,节约能源(3)因为总压恒定为100kPaC2H(g)2(2(g)C2H4(g)+HyO(g)平衡分压2.4%×100kPa4%×100kPa18%×100kPa12%×100kPa该温度下的平衡常数K2=486×10×12%×10045(kPa)(2.4%×100)×(4%×100)(4)由盖斯定律①一②+③得热化学方程式C2H(g)+CO2=C2H4(g)+CO(g)+H2O(1),则△H=(+136kJ·mol)-(-283.0kJ·mo-)+(-285.8kJ·mol-1)=+133.2k·mol-l;该工艺中碳与CO2反应生成CO,可以有效消除催化剂表面的积炭,维持催化剂活性(5)氢气移出率增大,生成物中氢气的浓度降低,有利于平衡正向移动,乙烷转化率增大;A点时乙烷的转化率为90%,生成H2的总物质的量为0.9mol,设平衡时体系中H2的物质的量为x,平衡体系中,c(乙烷)=0.1mo·-,c(乙烯)=0.9ml.1-,c(H1)=xmol·L,平衡常数K=0=0.,解得x0.09mol,则氢气移出率a≈=9.9-0.090.9×100%=90%

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