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问题 选择题

如图为一个装有活塞的密闭容器，内盛有22.4ml的NO，若通入11.2ml的O2（体积为标况下测得），保持温度，压强不变，则容器中的密度为（　　）

A．等于1.369g/L

B．等于2.054g/L

C．于1.369g/L和2.054g/L之间

D．大于2.054g/L

答案

一氧化氮与氧气恰好发生反应生成了二氧化氮，

2NO+O2 ═2NO2

2 1 2

22.4mL 11.2mL 22.4mL

反应后生成了22.4mL二氧化氮，假设二氧化氮体积不变，则容器中气体的密度为：ρ（NO2）=

46g/mol×
22.4×10-3L
22.4L/mol
22.4×10-3L
=2.054g/L，

因存在转化平衡：2NO2 ⇌N2O4，混合气体的体积减小，

所以容器中气体ρ应大于2.054g/L，

故选D．

单项选择题

卡兹等人指出，在社会政治问题上，意见领袖最重要的素质是（）

A.生活阅历

B.社会经济地位

C.社交性

D.社会政治地位
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多项选择题

Part 1: Self-introduction


·The interlocutor will ask you and your partner questions about yourselves. You may be asked about things like "your hometown ", "your interests ", "your career plans ", etc.

Part 2: Presentation


·The interlocutor gives you two photographs and asks you to talk about them for about one minute. The examiner then asks your partner a question about your photographs and your partner responds briefly. Then the interlocutor gives your partner two photographs. Your partner talks about these pictures for about one minute. This time the interlocutor asks you a question about your partner’s photographs and you respond briefly.

Part 3: Collaboration


·The interlocutor gives you and your partner a list of topics. Both of you need to choose one to discuss together. The interlocutor may join in the conversation and ask you questions, but you and your partner are expected to develop the conversation.

Topic 1:

Music in Modem Life

Topic 2:

Importance of Money

Topic 3:

An Extended Family or a Nuclear Family

Topic 4:

Taboos in China

Topic 5:

Differences between Life in a Big City and in the Country
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