选择题 化学反应a A + b B = d D + e E，已知40克A和21克B恰好完全反应生成28克D，则B、E两种物质的摩尔质量之比是
A. ![]()
600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060704/z52sddutyh3.png\" style=\"vertical-align:middle;\">∶![]()
600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060704/ue40ap42n5t.png\" style=\"vertical-align:middle;\"> B. ![]()
600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060704/czgty2n2nem.png\" style=\"vertical-align:middle;\">∶![]()
600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060704/sut33pjab0k.png\" style=\"vertical-align:middle;\"> C. ![]()
600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060704/zk0sxdad0fb.png\" style=\"vertical-align:middle;\">∶![]()
600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060704/41zrrzyuqgm.png\" style=\"vertical-align:middle;\"> D. ![]()
600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060704/41zrrzyuqgm.png\" style=\"vertical-align:middle;\">∶![]()
600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060704/1xmsisoglu2.png\" style=\"vertical-align:middle;\">
选择题 化学反应a A + b B = d D + e E，已知40克A和21克B恰好完全反应生成28克D，则B、E两种物质的摩尔质量之比是
A. ![]()
600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060704/z52sddutyh3.png\" style=\"vertical-align:middle;\">∶![]()
600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060704/ue40ap42n5t.png\" style=\"vertical-align:middle;\"> B. ![]()
600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060704/czgty2n2nem.png\" style=\"vertical-align:middle;\">∶![]()
600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060704/sut33pjab0k.png\" style=\"vertical-align:middle;\"> C. ![]()
600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060704/zk0sxdad0fb.png\" style=\"vertical-align:middle;\">∶![]()
600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060704/41zrrzyuqgm.png\" style=\"vertical-align:middle;\"> D. ![]()
600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060704/41zrrzyuqgm.png\" style=\"vertical-align:middle;\">∶![]()
600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060704/1xmsisoglu2.png\" style=\"vertical-align:middle;\">
本题答案：D
本题解析：由质量守恒可知，生成的E为33g；则B、E两者的物质的量比为方程式系数比：
![]()
600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060704/dgm254wbild.png\" style=\"vertical-align:middle;\">=![]()
600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060704/oppstwtkkfk.png\" style=\"vertical-align:middle;\">，可推得：![]()
600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060704/uk3nzplnzy1.png\" style=\"vertical-align:middle;\">=![]()
600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060704/41zrrzyuqgm.png\" style=\"vertical-align:middle;\">∶![]()
600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060704/1xmsisoglu2.png\" style=\"vertical-align:middle;\">，故答案为D
本题所属考点：【阿伏伽德罗常数】
本题难易程度：【一般】
Every man is his own enemy. 人都有与自己为敌的时候. /败事全由已.
