题干

亚氯酸盐(NaClO2)可作漂白剂,在常温下不见光时可保存一年,但在酸性溶液里因生成亚氯酸而发生分解:5HClO2=4ClO2↑+H++Cl+2H2O.开始时,分解反应非常慢,随后突然释放出很多的ClO2.对于以上分解速率变化的原因,下列猜测最合理的是(   )

A:酸使亚氯酸的氧化性增强

B:溶液中的H+起催化剂的作用

C:溶液中的Cl起催化剂的作用

D:逸出的ClO2使反应的生成物的浓度降低

上一题 下一题 0.0难度 选择题 更新时间:2014-01-09 06:51:54

答案(点此获取答案解析)

C

同类题1

阅读理解

    There's no doubt that our character has a profound effect on ourfuture. What we must remember, however, is not merely how powerful character isin influencing our fate (命运), but how powerful we are in shaping our own character and, therefore, our own fate. Character may determine our fate, but character is not determined by fate.

    It's a common mistake to think of character as something that is fully formed and fixed very early in life. It calls to mind old proverbs like“A leopard can't change its spots” and “You can't teach an old dog new tricks.”

    This perspective that our character is “etched in stone” is supported by a great deal of modern psychology emphasizing self-acceptance. As Popeye says, “I am what I am.” The hidden message is: Don't expect me to bemore, better, or different.

    Ultimately, these views of humanity totally under value the lifelong potential for growth that comes with the power of reflection and choice.

    How depressing it would be to believe that we can't choose to be better, more honest, more respectful, more responsible, and more caring. Noneof us should give up the personal seeking to improve our character. Not because we're bad, we don't have to be sick to get better, but because we're not asgood as we could be.

    There are so many things in life we can't control, whether we're beautiful or smart, whether we had good parents or bad, whether we grew up with affirmation or negation. It's inspiring to remember that nothing but moral willpower is needed to make us better.

    No, it isn't easy. But if we make a great effort to become moreaware of the habits of heart and mind that drive our behavior, we can begin to place new emphasis on our higher values so that we become what we want our children to think we are.