题干

将盛有NH4HCO3粉末的小烧杯放入盛有少量醋酸的大烧杯中.然后向小烧杯中加入盐酸,反应剧烈,醋酸逐渐凝固.由此可见(    )

A:NH4HCO3和盐酸的反应是放热反应

B:该反应中,热能转化为产物内部的能量

C:反应物的总能量高于生成物的总能量

D:每消耗0.1molNH4HCO3放出2.24L CO2

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答案(点此获取答案解析)

B

同类题3

根据短文内容,从短文后的选项中选出最佳选项。选项中有两项为多余选项。

    Susie Sunbeam was not her real name; that was Susan Brown. But every one called her Susie Sunbeam because of her such a sweet, smiling face.____.

    Her grandfather first gave her this name, and it seemed to fit the little girl so nicely that soon it took the place of her own.

    Even when a baby, Susie laughed from morning till night. ____.

    When she had learned to walk, she loved to go about the house and get things for her mother, and in this way save her as many steps as she could. She would sit by her mother's side for an hour at a time, and ask her ever so many questions, or she would take her new book and read

    ____ She never used an unkind word, but tried to do whatever would please her playmates best.

    One day, a poor little girl with a very ragged dress was going by and Susie heard some children teasing her and making fun of her. She at once ran out to the gate, and asked the poor little girl to come in. "What are you crying for?" Susie asked. "Because they all laughed at me," she said.

    ____ She cheered her up with kind words, and gave her a nice dress and a pair of shoes.

    This brought real joy and gladness to the poor child.____.

A. That's why we called her Susie Brown.

B. Susie was always pleasant in her play with other children.

C. No one ever heard her cry unless she was sick or hurt.

D. She always brought brightness with her when she came.

E. Susie liked to read books when her mother was busy in doing chores

F. And she thought that Susie was rightly called Sunbeam

G. Then Susie took the little girl into the house.