问题 选择题

NA表示阿伏加德罗常数,下列说法正确的是 (   )                      

A.1 mol Al分别放入足量的冷的浓HNO3、稀HNO3中,反应后转移的电子均为3NA

B.Na与足量O2反应生成1 mol Na2O或1 mol Na2O2均失去2NA个电子

C.各5.6 g铁分别与足量的盐酸、氯气反应,电子转移总数均为0.3NA

D.2.7 g铝与足量的NaOH溶液反应,转移的电子总数为NA

答案

答案:B

题目分析:Al在冷的浓硝酸中钝化,A项错误;铁与盐酸反应后生成Fe2+,铁与氯气反应后生成Fe3+,所以转移的电子数不相等,C项错误;2.7 g铝与足量的NaOH溶液反应,转移的电子总数为3NA,D项错误。答案选B。

点评:阿伏伽德罗常数是历年高考的“热点”问题。多年来全国高考化学试题出现的几率为100%。这双因为它既考查了学生对物质的量与粒子数、质量、气体体积和物质的量浓度之间的关系,又可以与物质结构、盐类水解、弱电解质的电离等其他的概念性知识点结合成综合性习题。

阅读理解

阅读理解。

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1. We can learn from the passage that _____.

A. Canada has 92 community colleges

B. to study in Canada is cheaper than in Australia

C. Canada spends the least on education among G-8 countries

D. 130,000 Chinese students enroll in Canadian universities every year

2. How long will you spend at least in total if you want to finish your Bachelor's,

Master's and Doctoral degrees in Canada?______

A. 11 years

B. 9 years

C. 8 years

D. 7 years

3. What advantages does Canada have to attract foreign students according to the passage?

(1) Quality education. (2) Safe environment

(3)Versatile culture (4) Bright job future

(5) High scholarship(6) Low tuition fees

A. (1) (2) (4) (5) (6)

B. (1) (2) (3) (5) (6)

C. (1) (3) (4) (5) (6)

D. (1) (2) (3) (4) (6)

4. What's the best title for the passage?______

A. Canadian culture

B. The life in Canada

C. Benefits of studying abroad

D. Study in Canada--- a unique experience

判断题