题目

San Francisco, a leader in urban recycling, is preparing to turn dog waste into energy. Norcal Waste System Inc., the city’s largest garbage company, plans to test collection carts(回收车)and collection bags in a city-center park which is popular with dog walkers. A city study found that almost 4 percent of all the garbage picked up at San Francisco homes was from animal waste, Norcal Waste spokesman Robert Reid said. San Francisco has about 120,000 dogs. “The city asked us to start a program to recycle dog waste in order to cut back adding more waste in landfills(废渣埋填池) “,R1.乙酸丁酯是重要的化工原料,具有水果香味.实验室制备乙酸丁酯的反应、装置示意图和有关信息如下:CH3COOH+CH3CH2CH2CH2OH$?_{△}^{浓H_{2}SO_{4}}$CH3COOCH2CH2CH2CH3+H2O(1)乙酸丁酯粗产品的制备在干燥的50mL圆底烧瓶中,装入沸石,加入12.0mL正丁醇和16.0mL冰醋酸(过量),再加3~4滴浓硫酸.然后再安装分水器(作用:实验过程中不断分离除去反应生成的水)、冷凝管,然后小火加热.将烧瓶中反应后的混合物冷却与分水器的酯层合并.装置中冷水应从b(填“a”或“b”)管口通入;通过分水器下端旋塞分出的生成物是水,其目的是分离酯化反应生成的水,使平衡正向移动,提高反应产率.(2)乙酸丁酯的精制,将乙酸丁酯粗产品用如下的操作进行精制:①水洗、②蒸馏、③用无水MgSO4干燥、④用10%碳酸钠洗涤.①正确的操作步骤是C(填标号).A.①②③④B.③①④②C.①④①③②D.④①③②③②分液漏斗有两种,如图.分液时应选择图中梨形分液漏斗,其原因是梨形分液漏斗靠近旋塞处比较细长,双液界面更清晰,分离更完全.③蒸馏操作时,需收集126℃的馏分,沸点大于140℃的有机化合物的蒸馏,一般不用上述冷凝管而用空气冷凝管,可能原因是防止因温差过大,冷凝管炸裂.(3)计算产率,测量分水器内由乙酸与丁醇反应生成的水体积为1.8mL,假设在制取乙酸丁酯过程中反应物和生成物没有损失,且忽略副反应,计算乙酸丁酯的产率为62.5%.
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