已知木炭在一定条件下与浓硝酸反应生成两种+4价的氧化物,为了探究一氧化氮(NO)

题型:实验题

问题:

已知木炭在一定条件下与浓硝酸反应生成两种+4价的氧化物,为了探究一氧化氮(NO)能否与过氧化钠反应,以及反应后的产物中是否有亚硝酸钠(NaNO2),某小组同学设计了如图所示装置(夹持仪器和连接用的胶管已经省略)。

(1)为了完成该实验,虚线框内还需要连接B~E四套装置,按气流方向连接的顺序为:

a→(       )(       )→(       )(       )→(       )(       )→ (       )(       )(填仪器接口的字母编号)。连接好仪器,检查气密性,装入药品后,要通入一段时间的氮气,再滴加浓硝酸,点燃酒精灯,通入氮气的主要目的是                  

(2)装置E中观察到的主要实验现象有               

(3)装置C的作用是                                     

(4)某同学经查阅资料后发现亚硝酸是弱酸,性质不稳定,室温下易分解生成一氧化氮。装置D中充分反应后,设计实验证明D中是否有亚硝酸钠生成:                    。(写出检验步骤及现象)。

(5)亚硝酸钠在酸性条件下可将I氧化为I2,同时生成NO,该反应常用于亚硝酸钠含量的测定,请写出该反应的离子方程式:       

考点:物质的分离离子的检验粗盐的提纯
题型:实验题

阅读理解。

                                                        Some Advice on Travel

     1. Forget fashion (时尚)! Always wear your most comfortable clothes when going on long journeys.

     2. Traveling on trains and buses can be boring, so take a good book to read.

     3. If you're going somewhere cold, remember your warm clothes!

     4. Or, if you are going somewhere sunny, remember to wear sunblock (防晒霜) and sunglasses.

     5. Always take a camera with you to capture those special moments.

     6. Be careful with your things whenever you go to busy places, like a train station. There are often

thieves there! 

     7. Always leave room (空间) in your bag for buying presents on the way home. 

     8. Most countries have lower prices for students, so if you have one, take your student card with

you and save money.

      9. Bus tours often stop at expensive shops along the way, save your money by buying presents at

local shops.

      10. If you travel abroad, remember to take your passport (护照). Whatever you do, don't lose it!

1. If you go to Hainan Island for a trip in summer, you should take            with you. [ ]

A. warm clothes and sports shoes

B. sunglasses and sunblock

C. fashionable clothes and a big bag

D. some fruit and drinks

2. According to the passage,            is a good way to keep away from boredom (单调) while you

    are on a train or a bus. [ ]

A. taking a camera

B. reading a good book

C. listening to music

D. sleeping for some time

3. You must always            while you are at some busy places because there are often thieves there. [ ]

A. put your things away

B. look after your things well

C. give your things away

D. get your things ready

4. If a student wants to buy some presents at lower prices while traveling, he should show            to

    the shop assistant. [ ]

A. prices

B. his things

C. his passport

D. his student card

5. The underlined word "capture" in this passage means           . [ ]

A. 拍摄

B. 感受

C. 抓住

D. 控制

题型:实验题

图是广州、武汉、北京和哈尔滨四地气候统计图,其中能反映北京气候特点的是

A.①

B.②

C.③

D.④

题型:实验题

从()来看,团队之间的冲突可以分为建设性冲突与破坏性冲突两类。

A.冲突的内容

B.冲突的性质

C.冲突的作用

D.冲突的实质

题型:实验题

经济学上所说的需求总是同时涉及该商品的销售价格和()这两个变量。

A、人们愿意购买的该商品的数量

B、人们在某种价格水平上有能力购买的该商品的数量

C、人们在某种价格水平上愿意购买的该商品的数量

D、人们在某种价格水平上愿意并且有能力购买的该商品的数量

题型:实验题

环绕北极的国家不包括下列的()。

A、美国

B、挪威

C、丹麦

D、芬兰

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