题目内容
FeS2在空气中充分燃烧的化学方程式为4FeS2+11O2![](http://thumb.1010pic.com/pic6/res/gzhx/web/STSource/20131031223358680508835/SYS201310312233586805088009_ST/0.png)
A.120N/a
B.120a/11N
C.11a/120N
D.120N/11a
【答案】分析:反应中Fe元素化合价由+2升高为+3价,S原子化合价由-1价升高为+4价,氧元素化合价由0价降低为-2价,根据n=
计算a g FeS2的物质的量,再根据方程式计算参加反应的氧气的物质的量,计算转移电子物质的量n,根据N=nNA计算阿伏伽德罗常数.
解答:解:agFeS2的物质的量为
=
mol,由方程式4FeS2+11O2
2Fe2O3+8SO2可知,参加反应的氧气的物质的量为
mol×
=
mol,反应中氧元素化合价由0价降低为-2价,故转移电子物质的量为
mol×2×2=
mol,所以N=
mol×NA,故NA=
mol-1,
故选D.
点评:本题考查氧化还原反应的有关计算、阿伏伽德罗常数等,难度不大,注意基础知识的理解掌握.
![](http://thumb.1010pic.com/pic6/res/gzhx/web/STSource/20131031223358680508835/SYS201310312233586805088009_DA/0.png)
解答:解:agFeS2的物质的量为
![](http://thumb.1010pic.com/pic6/res/gzhx/web/STSource/20131031223358680508835/SYS201310312233586805088009_DA/1.png)
![](http://thumb.1010pic.com/pic6/res/gzhx/web/STSource/20131031223358680508835/SYS201310312233586805088009_DA/2.png)
![](http://thumb.1010pic.com/pic6/res/gzhx/web/STSource/20131031223358680508835/SYS201310312233586805088009_DA/3.png)
![](http://thumb.1010pic.com/pic6/res/gzhx/web/STSource/20131031223358680508835/SYS201310312233586805088009_DA/4.png)
![](http://thumb.1010pic.com/pic6/res/gzhx/web/STSource/20131031223358680508835/SYS201310312233586805088009_DA/5.png)
![](http://thumb.1010pic.com/pic6/res/gzhx/web/STSource/20131031223358680508835/SYS201310312233586805088009_DA/6.png)
![](http://thumb.1010pic.com/pic6/res/gzhx/web/STSource/20131031223358680508835/SYS201310312233586805088009_DA/7.png)
![](http://thumb.1010pic.com/pic6/res/gzhx/web/STSource/20131031223358680508835/SYS201310312233586805088009_DA/8.png)
![](http://thumb.1010pic.com/pic6/res/gzhx/web/STSource/20131031223358680508835/SYS201310312233586805088009_DA/9.png)
![](http://thumb.1010pic.com/pic6/res/gzhx/web/STSource/20131031223358680508835/SYS201310312233586805088009_DA/10.png)
故选D.
点评:本题考查氧化还原反应的有关计算、阿伏伽德罗常数等,难度不大,注意基础知识的理解掌握.
![](http://thumb2018.1010pic.com/images/loading.gif)
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