2018-2022学年英语周报高二外研第6期答案

27.(1)S(写“S”或“S”等均给分,1分)(2)Sb+3Fe3+-3Fe2++Sb3+(2分)(3)2(2分)(4)减少氨水的用量,节约成本(2分)(5)排除溶液中的O2,防止Fe2+被氧化(2分)(6)NaC|O加入过多(2分)(7)正极(1分);4OH-+SO-2e-90-+2H2O(2分)【解析】本题主要考查制备锑白和磁性纳米FeO4胶体的工艺流程,考查学生对元素化合物的理解能力和综合运用能力。(1)根据氧化还原知识和流程图信息,推断出单质X是沉淀S(2)Fe3+比Fe2+更容易被沉淀,故为了后续步骤锑铁分离而将Fe+还原为Fe2+(3)略。(4)SbC水解的第一步反应的化学方程式为SbCl+H2O-SOCl↓+2HCl,水解的第二步反应的化学方程式为2SbOC+2H2O-Sb2O·H2O+2HCl,第一步产生的盐酸也会消耗氨水。(5)通入H2的目的是排除溶液中的O2·防止Fe2+被氧化。(6)Fe3O4胶体中混有较多的Fe(OH)3,说明更多的Fe2+被氧化,原因有二:一是被 NaClo3氧化,二是被溶液中溶解的Oh氧化(7)略。【评分细则】(1)写名称不给分(2)未配平,但反应物和生成物均写对了给1分(4)答减少环境污染得1分(5)答防止制备过程中生成的Fe(OH)z被氧化等合理答案均给分

Dear davidHaving learned that COVID-19 is becoming widespread in your country, I am really concernedabout you. Here I am writing to offer you some suggestions, which I hope will be of some help to youTo begin with, it is necessary that you stay at home and reduce outdoor activities as much as possibleIf you do need to go out, please wear a mask to avoid being infected. In addition, whenever you arein the open air; always remember to keep about one meter away from others. Last but not least, youdbetter keep good healthy habits such as washing your hands and doing more indoor activities nsincerely hope that you take my suggestions into consideration- LIRYours sincerelyLi hu

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