英语周报母版新目标实验七年级2021-2022第9期答案

Sir years later, Radice found himself a patient atSt. Barnabas, infected with COVID-19. He couldn'tbelieve he was looking up into the eyes of the man whoseconfidence hed restored. At this time when doctorscouldn't help but be anxious, Pitera, once surrounded byworry, said he was able to deal with the stress far betterthan he would have before his heart attack. For Radicethose words "Not on my watch" were exactly what heneeded to hear. Slowly, day by day, his condition wasgetting better and better. Radice began his own exerciseprogram.Pitera visited as often as he could to cheer onRadices progress. Nearly 20 days after he wasadmitted, Radice was allowed to leave the hospital. Piteracame to his room to say goodbye."You saved my life,Radice told him. "You saved my life, " Pitera answeredback. Hospital employees lined the hallwaysapplauding, as Radice was wheeled to his wife waitingoutside."We have a lot of tough days ahead of usPitera said."Dan boosted a lot of people,s spirits justwhen we needed it

26.(1)同分异构体(1分(2)蒸馏烧瓶;平衡分液漏斗与烧瓶内的压强,使浓硫酸顺利流下(各1分)(3)①冷水浴(1分)②生成的NOSO1H作该反应的催化剂(1分)③装置A中的水蒸气会进入装置B中使 NOSO H水解(1分)④防止空气中的水蒸气进入装置B中使 NOSO,H水解;吸收尾气SO2,防止污染环境(各1分)⑤2 NOSO H+H2O=2H2SO4+NO↑十NO2↑(2分)(4)①滴入最后一滴草酸钠溶液时,溶液由浅红色变为无色,且半分钟內不恢复红色(1分)②93.38%(3分)解析:本题考査亚硝酰硫酸的制备与纯度测定实验。装置∧是利用亚硫酸钠和浓硫酸反应:NaSO;十H2SO4—Na2SO4+SO↑十H2O制取SO2,制取的SO2通入装置B中,HNO3与SO2在浓H2SO4作用下于冷水浴中反应制得 NOSO,H。(2)根据分析,导管a的作用是平衡分液漏斗与烧瓶内的压强,使浓硫酸顺利流下(3)①该反应必颁维持体系温度不得高于20℃,采取的措施除了加快搅拌速度外,还可以将三颈烧瓶置于冷水浴中。②开始时反应速率缓慢,待生成少量 NOSO H后,温度变化不大,但反应速率明显加快,其原因是生成的 NOSO, H作该反应的催化剂。③由于亚硝酰硫酸遇水分解,该实验装置存在可能导致 NOSO H产量降低的缺陷是装置A中的水蒸气会进入装置B中使 NOSO H水解。④根据分析,装置C的作用是防止空气中的水蒸气进入装置B中使 NOSO, H水解,同时还可以吸收尾气SO2,防止污染环境。⑤ NOSO H遇水分解时发生反应的化学方程式为2NOSO4H+H2O=2H2SO4+NO↑+NO2↑。(4)根据滴定实验操作,用0.2500mol·L-的草酸钠标准溶液滴定过量的KMnO标准溶液,草酸钠与KMnO4发生氧化还原反应:2MnO+5C2O+16H=2Mn2++10)↑+8H2O,由反应可知,过量的KMO物质的量为mCO)=3×0.20m1:1021=0.02m,则MxH溶液反应的KMnO标准溶液的物质的量为0.06L×0.1000mol·L.1-0.002mol=0.004mol,根据配平后的反应2KMnO4+5 NOSO H+2H2O=K2SO4+2MnSO4+5HNO2+2H2SO4可知,产品中 NOSO, H的物质的量为2×0m-0mo,则亚硝酰硫酸的纯度为01m.3E:m×109389

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