题干

设NA为阿伏加德罗常数的数值,下列说法错误的是(  )

A:一定条件下,2molSO2和1molO2混合在密闭容器中充分反应后容器中的分子数大于2NA

B:0.1mol铁粉与足量水蒸气反应生成的H2分子数目为0.1NA

C:由1molCH3COONa和少量CH3COOH形成的中性溶液中,CH3COO数目为NA

D:分子数目为0.1NA的N2和NH3混合气体,原子间含有的共用电子对数目为0.3NA

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答案(点此获取答案解析)

B

同类题4

阅读下面短文,在空白处填入1个适当的单词或括号内单词的正确形式。

    UN Chinese Language Day ____ (celebrate) yearly on April 20. This year, Doreen Hynd was among those invitees, who are either experts on the Chinese culture ____ have a special skill related to it.

    Hynd astonished all those present while performing Tai Chi, ____ Chinese martial (武术的) art form, at an event held by the UN Tai Chi Club. The audience could hardly believe she was a 93-year-old grandma. It was definitely amazing that she could bend her body and raise her leg so ____ (easy) and keep herself still standing on one leg.

    Hynd owes (归功于) all this to her continuous practice of Tai Chi.

    Born in Australia in 1925, Hynd began Tai Chi training in her 50s and then moved to the US, ____ she later became an instructor herself.

    When ____ (ask) about the greatest benefit she gained from Tai Chi, Hynd said, “balance.” Hynd has been teaching people of all ages and different ____ (culture) backgrounds how to practice Tai Chi. They have benefited greatly from their association with the Chinese culture. They've developed a balanced state of mind and improved their health after ____(month)of practice. Tai Chi allows these people ____(understand)that, from the perspective(视角)of yin and yang, all things are closely connected with each other. This might be where the attraction of Tai Chi ____(lie). Hynd enjoys sharing this great gift from China with her students.