题目

常用调味剂花椒油是一种从花椒籽中提取的水蒸气挥发性香精油，溶于乙醇、乙醚等有机溶剂。利用如图所示装置处理花椒籽粉，经分离提纯得到花椒油。实验步骤：ⅰ.在A装置的圆底烧瓶中装入2/3容积的水，加1~2粒沸石。在B的圆底烧瓶中加入20 g花椒籽粉和50 mL水。ⅱ.加热A装置中的圆底烧瓶，当有大量蒸气产生时关闭弹簧夹，进行蒸馏。ⅲ.向馏出液中加入食盐至饱和，再用15 mL乙醚萃取2次，将两次萃取的醚层合并，加入少量无水 ；将液体倾倒入蒸补全对话根据对话内容，从方框内选择恰当的句子将对话补充完整。(选项中有两项是多余的)A: Excuse me, sir. 1.B: Certainly. Go along this street. Turn left into Xingfu Street, and the museum is on your right.A: 2.B: It’s about thirty minutes.A: I see. 3.B: Yes, you can. A No. 103 bus will take you there.A: 4.B: Over there. Look! The bus is coming.A: Thank you very much.B: 5.