题干

某同学按下列步骤配制100mL0.200mol•L1Na2CO3溶液,请回答有关问题.
实验步骤有关问题
(1)计算所需Na2CO3的质量需要Na2CO3的质量为____
(2)称量Na2CO3固体称量过程中应用到的主要仪器是____
(3)将Na2CO3加入100mL烧杯中,加入适量蒸馏水为了加快溶解速率,常采取的措施是____
(4)将烧杯中的溶液转移至仪器A(已检查不漏水)中①在转移Na2CO3溶液前应将溶液____
②仪器A是____
③为防止溶液溅出,应采取的措施是____
(5)向仪器A中加蒸馏水至刻度线在进行此操作时应注意的问题是____
(6)摇匀、装瓶,操作B,最后清洁、整理 操作B是____
讨论按上述步骤配制的Na2CO3溶液的浓度____(选填“是”或“不是”)0.200mol•L1.理由是____
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答案(点此获取答案解析)

2.12g,\u5206\u6790\u5929\u5e73\u6216\u7535\u5b50\u5929\u5e73,\u7528\u73bb\u7483\u68d2\u6405\u62cc,\u51b7\u5374\u81f3\u5ba4\u6e29,100mL\u5bb9\u91cf\u74f6,\u7528\u73bb\u7483\u68d2\u5f15\u6d41,\u52a0\u84b8\u998f\u6c34\u81f3\u5bb9\u91cf\u74f6\u4

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阅读理解

    Dear Student of Star Middle School:

    As your student council president, I am writing to ask for your support to start the Count-Your-Steps walking program. Mr. Stewart Thomas, a parent of two students at Star Middle School, firstly came up with the idea. Mr. Thomas is a fan of walking and wants to encourage others to appreciate the activity. He shared his idea with our principal, Ms. Howser, who immediately agreed that we should try it.

    Ms. Howser contacted the other middle schools in the district, and all the teachers eagerly adopted the program. Now a team of Count-Your-Steps organizers made up of representatives from the middle schools, has established the program's goal: to increase awareness of the benefits of walking. Organizers want middle school students to accept this challenge and make walking one of their daily activities.

    The program has clear guidelines. Interested participants must only commit to recording the number of steps taken daily. Ms. Earley, the assistant principal, will give each of us a log for recording our steps and a pedometer, which is a small, digital tool used to count the steps of the person wearing it. All participants need to do each day is to wear the pedometer, walk as much as possible, and then record the number of steps in our logs. Clearly, the process is simple and convenient.

    While the benefits of walking are multiple, this challenge offers all who participate the opportunity to work together, achieve success, and make positive changes. Remember that the other schools in the district are signed up for the Count-Your-Steps too, and each one will try to take more steps than our school. I hope many will agree to this challenge and show everyone the Star Middle School Cougar Spirit.

    Please take into careful consideration this valuable and well-planned program, and then sign up today! In the words of Mr. Thomas, “Together we can enjoy the advantages of walking.”

    Sincerely,

    Cora Jeffries