题干

某小组在学习“二氧化碳与氢氧化钠溶液反应”时,进行了如下探究,

【提出问题】二氧化碳与氢氧化钠反应,还是溶解在水中?

【查阅资料】

①15℃、101KPa时,二氧化碳的溶解度如下:

溶剂

酒精

溶解度

1.0

0.5

②15℃时,在酒精中氢氧化钠易溶、碳酸钠微溶.

③通常情况下,稀溶液的体积约等于溶剂的体积.

【实验设计】在15℃、101KPa时,制取二氧化碳并用于实验甲、实验乙.

【分析与表达】

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    “Just sign here, sir.” the deliveryman said as he handed Oscar Reyna a package.

    The package consisted of a long, narrow box1wrapped in brown paper. 2 the box, Oscar saw an umbrella inside — a very old one with a beautifully carved handle._3 he had not seen it for more than 20 years, he recognized it 4

    Oscar was 16 when he first saw the5umbrella. He had gone to a concert with his grandparents. As they were leaving, he noticed an umbrella on an empty seat. Impressed by its6 Oscar felt a strong desire to find its7.

    Oscar 8the manager to look in the record of advance ticket sales. Just as he thought, a name matched the seat 9Oscar had found the umbrella. The name was Mrs. Katie O'Brien.

    Oscar talked his grandparents into going by Mrs. O'Rrien's 10 on their way home. He rang the bell, the door opened, and an elderly woman appeared. “May I 11 you? ” she asked. “I'd like to return it if it's yours.” Oscar said, 12 the umbrella as if presenting a13 that had long been wished for. “Why, yes! It's mine.” replied Mrs. O'Brien with a14 smile and shining eyes. “It was given to me by my father years ago. Thank you so much for returning it. May I offer you a reward for your 15?” “No, ma'am,” he said, “my grandmother says that a good deed is its own reward.” “Well, that's 16 what my father used to say. What is your name? Young man?”

    Years later, Oscar was staring at the finely carved handle of the umbrella as he remembered Mrs. O'Brien. It was in perfect condition, considering how17 it was. Why had it arrived here today? As if 18 a note fell from the paper. It read: Mrs. O'Brien wanted you to 19 this umbrella as a present for a kind, 20gesture long ago.