BD
分析:A、O
2和O
3的組成元素都為O元素,根據(jù)n=
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=
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計算;
B、根據(jù)n=
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=
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計算;
C、根據(jù)過氧化鈉的物質(zhì)的量和O元素的化合價分析;
D、根據(jù)鈉的物質(zhì)的量和化合價分析.
解答:A、O
2和O
3的組成元素都為O元素,n=
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=
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=2mol,所含原子數(shù)為2N
A,故A錯誤;
B、標(biāo)準(zhǔn)狀況下,11.2LSO
2的物質(zhì)的量為
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=0.5mol,含有的分子數(shù)為0.5N
A,故B正確;
C、7.8g過氧化鈉為0.1mol,與足量水反應(yīng),自身發(fā)生氧化還原反應(yīng),轉(zhuǎn)移電子數(shù)為0.1N
A,故C錯誤;
D、23g鈉的物質(zhì)的量為1mol,最高化合價為+1價,與足量氧氣充分反應(yīng),轉(zhuǎn)移的電子數(shù)一定為是N
A,故D正確.
故選BD.
點評:本題考查阿伏加德羅常數(shù),題目難度不大,注意物質(zhì)的組成、性質(zhì)等問題.