题干

洪源同学用下图总结了NaOH的四条化学性质(即NaOH与四类物质能够发生化学反应)

(1)为了验证反应①,洪源将无色酚酞试液滴入NaOH溶液中,溶液由无色变成____
(2)为了验证反应③能够发生,你选择的物质是____

A.Na2CO3B.HClC.FeCl3D.Ba(NO)2

(3)郑老师在配制氢氧化钠溶液时,发现盛装氢氧化钠固体的瓶盖未盖严,已有部分固体变质,其在空气中变质化学反应方程式为____,洪源同学帮郑老师想了一个办法:先用该固体配成溶液,再向该溶液中加入____溶液至不再产生沉淀为止,然后进行____操作,就得到了所需的纯净的氢氧化钠溶液。
(4)洪源利用郑老师配制的氢氧化钠溶液做了以上碱的性质的相关实验,为了处理实验后的废液,需要知道废液的酸碱度,洪源的操作是____

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答案(点此获取答案解析)

\u7ea2\u8272,C,NaOH+CO2=Na2CO3+H2O,Ca(OH)2

同类题1

阅读下面短文,掌握其大意,然后从每题所给的四个选项中选出最佳选项。


    Asha looked out of the window on the plane. What a  1 ! The buildings were so tall. The city was large, much larger than her small town.

    Asha was on vacation in New York City. She was very   2  as she had always wanted to come since she was young. She read stories about it and studied its   3 . She knew how the island of Manhattan was bought from native Americans 300 years ago. She   4  knew people from all over the world came to live here. These people, like Asha,   5 a new life in New York.

    But Asha was only staying for fourteen   6 . She thought of these two weeks as a time to  7  herself to move back to New York. She would return to her small  8  , stay for one year, and then come to live in New York forever. So she had to plan this vacation   9.

    In New York Asha wanted to do10things. First, she wanted to look for a job. Next, she would find a place to live. She knew it was expensive to live in New York and that finding a good place to live was  11. And the third thing she wanted to do was to   12  her English. She had studied English for 12 years but didn't know  13   she could understand “real” English.

    Before leaving, her friends told her that New York was a14place. But Asha wasn't worried. She had studied New York carefully. She believed she would be safe.

      15   Asha saw the Statue of Liberty! The plane flew around it, and then began to slow down. Soon Asha was on the ground, getting ready to leave the plane — to greet her future.