练习册

  • 练习册
  • 试题
    精英家教网 > 初中地理 > 题目详情

    【题目】下表是某实验报告中的一组数据：

    实验

    序号

    试剂1

    试剂2

    混合前

    温度/℃

    混合后最高或最低温度/℃

    ①

    3.2 mL水

    3.2 g Na2CO3固体

    20

    24.3(t1 )

    ②

    35 mL稀盐酸

    3.2 g Na2CO3固体

    20

    25.1(t2 )

    ③

    35 mL水

    2.5 g NaHCO3固体

    20

    18.5(t3 )

    ④

    35 mL稀盐酸

    2.5 g NaHCO3固体

    20

    16.2(t4)

    （1）从实验①、③数据可知：Na2CO3溶于水________热量，NaHCO3溶于水________热量(填“放出”或“吸收”)。

    （2）根据t2>t1 可知Na2CO3与稀盐酸反应______热量，根据t4<t3 可知：NaHCO3与稀盐酸反应______热量(填“放出”或“吸收”)。

    【答案】（1）放出 吸收 （2）放出 吸收

    【解析】

    试题分析：（1）从实验①、③数据可知：Na2CO3溶于水溶液温度升高，即Na2CO3溶解时可放出热量。NaHCO3溶于水溶液温度降低，即NaHCO3溶解时可吸收热量。

    （2）根据t2>t1 可知Na2CO3与稀盐酸反应放出热量，根据t4<t3 可知：NaHCO3与稀盐酸反应吸收热量。

    练习册系列答案
    年级 高中课程 年级 初中课程
    高一 高一免费课程推荐！ 初一 初一免费课程推荐！
    高二 高二免费课程推荐！ 初二 初二免费课程推荐！
    高三 高三免费课程推荐！ 初三 初三免费课程推荐！
    相关习题

    科目：初中地理 来源： 题型：

    【题目】I am an American boy. ___name is Paul. I am 12 . I___two friends, Sally and Mona. They’re___. We play sports___. We play soccer, basketball, volleyball and____ Sally___a sports collection（收藏）.___has seven soccer balls,___basketball, four volleyballs, and six tennis rackets. We often(经常)___volleyball on TV. What sports____you often play?

    【1】A. My B. His C. Her

    【2】A. am B. do C. have

    【3】A. them B. brothers C. sisters

    【4】A. everyday B. every day C. morning

    【5】A. sports B. more C. them

    【6】A. doesn’t have B. plays C. has

    【7】A. He B. She C. Paul

    【8】A. one B. zero C. three

    【9】A. play B. have C. watch

    【10】A. do B. does C. don’t

    查看答案和解析>>

    科目：初中地理 来源： 题型：

    【题目】欲除去下列物质中的杂质，把适用的试剂、操作方法的序号写在相应的横线上。

    ①加适量盐酸、过滤、蒸发；②加适量水、过滤、蒸发；③加适量水、过滤；④加热(或高温灼烧)；⑤加适量盐酸、蒸发。

    （1）碳酸钙中含有少量Na2CO3：________。

    （2）KCl粉末中含有少量K2CO3：________。

    （3）CaO中含少量CaCO3：________。

    （4）MnO2中含有少量炭粉：________。

    （5）KCl中含有少量MnO2：________。

    查看答案和解析>>

    科目：初中地理 来源： 题型：

    【题目】词语运用（10小题，每小题1分，共10分）

    用括号内所给单词的适当形式填空。

    先阅读短文，掌握其大意。然后从方框中所给的词中选出恰当的10个，并用其适当形式填空，每个词限用一次。（每小题1分）

    to, at, she, his, up, go, think, classes, has, doesn’t, because, watch

    Edward is my friend. He often gets 1 at 6:30 every morning. Then he 2 to school at 7:30. He 3 math at eight o’clock and history at nine. Math is 4 favorite subject. He likes it, 5 it’s very interesting. But he 6 like history, he 7 it’s boring. Mrs. Jones is his math teacher. 8 is very nice. He eats lunch 9 school, and he eats dinner at home. After dinner he watches TV for half an hour. He likes 10 TV. Then he does his homework. He goes to bed at 9:00.

    查看答案和解析>>

    科目：初中地理 来源： 题型：

    【题目】A

    Many people like animals such as dogs and cats and keep one or more of them as pets. If you keep a dog or a cat as a pet, you must know how to look after it.

    A grown-up dog needs two meals a day — not more. It can eat meat, fish, rice and some other things. Dogs like large bones(骨头), but you can’t give them chicken bones. Remember to give them much clean water.

    A dog should have a clean, dry box for sleeping. Washing it once a week is good for its health. If it is ill, take it to a doctor. A healthy dog will bring you more pleasure.

    Be careful when you choose a cat. A cat has two meals a day with some meat or fish. It drinks a little milk every day. Sometimes you can give it vegetables to eat. Don’t forget that it needs clean water to drink.

    Take good care of your pets, they will be your good friends. Maybe they can give you some help when you are in need.

    【1】 Many people keep __________ as pets.

    A. pandas B. elephants C. chicken D. cats

    【2】 What do dogs like eating?

    A. All the bones. B. Big bones.

    C. Chicken bones. D. Small bones.

    【3】 A healthy dog can make you __________.

    A. happy B. trouble C. cry D. ill

    【4】 Cats usually drink __________.

    A. orange B. red ink C. apple juice D. milk and water

    【5】Will pets be people’s friends according to /span>the article?

    A. No, I don’t think so. B. Yes, but only a little.

    C. Yes, they will. D. No, they won’t.

    查看答案和解析>>

    科目：初中地理 来源： 题型：

    【题目】 I like __________ and __________.

    A. tomato, rices B. tomatoes, rice

    C. tomatoes, rices D. tomato, rice

    查看答案和解析>>

    科目：初中地理 来源： 题型：

    【题目】I have an __________ book. Let’s read(阅读) it now.

    A. good B. fun

    C. boring D. interesting

    查看答案和解析>>

    科目：初中地理 来源： 题型：

    【题目】 I decided to go with them, __________ I had nothing better to do.

    A. though B. because C. so D. until

    查看答案和解析>>

    科目：初中地理 来源： 题型：

    【题目】下列对实验现象或结论的描述中错误的是（ ）

    A．碘易溶于水

    B．高锰酸钾几乎不溶于汽油

    C．水和植物油混合后用力振荡可形成乳浊液

    D．乙醇能与水互溶

    查看答案和解析>>

    同步练习册答案