题干

某兴趣小组欲测定市场上某H2O2消毒液质量分数,现进行如下操作

己知:2MnO4﹣+5H2O2+6H+═2Mn2++8H2O+5O2

操作①:取10.00mLH2O2溶液(密度为1.00g•mL﹣1)置于锥形瓶中加水稀释,再加稀硫酸酸化;

操作②:用0.200 0mol•L﹣1KMnO4溶液滴定;

操作③:用同样方法滴定,4次消耗KMnO4溶液的体积分别为20.00mL、19.98mL、20.02mL、22.00mL.请回答下列问题:

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同类题1

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中国的“德治”传统

    在社会治理问题上,中国古代很早就产生了德治思想,并形成德治传统。德治思想的源头可追溯到尧舜时代。关于德治的记载,最早成书于周代的《诗经》《尚书》中。《诗经》不少诗篇蕴含着前代圣贤以德治国的思想,《尚书》中提出了“敬天保民”“以德配天”的命题。要保住天命,就必须敬德,以祈天永命,勤政爱民,得到民众的真心归附。德治思想的另一含义是“明德慎罚”。提倡德治并非不要刑罚,而是强调实施教化,先教后罚,以刑辅德,不专以刑杀立威。“明德慎罚”将道德教化与刑罚措施糅合,奠定了中国古代治国的基本理念。孔子继承周代的德治思想,强调治国要以礼乐为核心,突出教化作用。社会秩序井然,人际间和谐相处,是孔子希望通过德治达到的理想状态。

    德治思想是“周孔之教”的重要组成部分,后世政治家、思想家不断探索,深化了德治思想的内涵。

    战国时,沿着孔子的思路,孟子提出了一系列仁政主张。他主张“以德服人”,反对用严刑峻法治理国家,提倡“省刑罚”,教育百姓做到孝悌忠信。西汉初,陆贾告诫刘邦。提出了“治以道德为上”的观点。汉武帝时,董仲舒提出“罢黜百家,独尊儒术”,为汉代德治思想定下了基调。他认为治理国家不能只靠刑罚,要通过教化培养人的是非荣耻之心,德治思想成为政治领域的主导思想。

    唐朝前期,隋朝二世而亡对唐初君臣是严厉的警示。唐太宗说:“为国之道,必须抚之以仁义,示之以威信……”既要发挥道德教化的作用,也要发挥法律的制约作用,二者不可割裂,互为补充。在刑罚的施用上,唐初务在宽简。在唐太宗等人德治思想影响下,唐高宗、武则天时期,遵循先人遗训,缓刑用仁,谨慎治国,天下大治。

    宋代理学形成阶段,德治思想深深打上了理学烙印。朱熹从人心的角度解释德治。仁心表现在政策上就是爱民如子、平易近人、爱惜民力等。理学诸子概括出了“三纲八目”的治国模式,期望君主志向确定而达到天下大治。理学家提倡教化,整肃人心,通过书院讲习等传授儒家伦理,为实现“修身齐家治国平天下”提供了良好的社会环境。后世产生“天下兴亡、匹夫有责”的国家意识,与理学家及其追随者的讲学不无关联。 德治思想从确立始,历经几千年的演进,围绕“礼法并治、德主刑辅”的逐渐深入,为社会治理提供了指导思想。当今社会,依法治国作为基本国策,强调法律的权威性、严肃性,任何人不能凌驾于法律之上。有人认为法治与德治不能并存,否定“以德治国”。古代社会提倡德治并非不讲法治,而是主张加强教化,做到礼法并用,宽猛相济。我们要借鉴古代重视教化的传统,为“依法治国”打下“以德治国”的根基,用社会主义核心价值观引领人们的生活,使大家自觉遵守社会规范,走出一条有中国特色的法治现代化道路。

(选自2015年4月13日《光明日报》,有删改)

同类题4

阅读下面短文,掌握其大意,然后从各题所给的A、B、C和D项中,选出最佳选项。

       When the weather turns warm, everyone wants to be in or around the water. Hanging out at the pool or the beach on a hot day is a great way to beat the heat.

       Most people don't think much about water 1—but they should. For people between the ages of 5 and 24, drowning is the second  2 cause of accidental death.

       It doesn't have to be that way,  3.By knowing how to stay safe and following a few simple guidelines, most water related accidents can be  4.

       It's a good idea to swim only in places that are watched over by a lifeguard. 5  can predict changing ocean currents, sudden storms, or other  6  dangers. In the event that something does go wrong, lifeguards are trained in  7  techniques.

       Swimming in an  8 body of water(like a river, lake, or ocean) is different from swimming in a pool. You need more  9 to handle the currents and other changing conditions in the open water.

       If you do find yourself  10  in a current, don't panic and don't fight the current. Try to swim parallel(平行) to the shore until you are able to  11  the current, which is usually a narrow channel of water.  12  try to make your way back to shore as you do so. If you're  13  to swim away from the current, stay calm and 14 with the current. The current will usually  15,then you can swim to shore.

       16  a very good swimmer who tries to swim against a strong current will get worn out. If you're going to  17  in open water, better take lessons that provide you with tips on  18  unexpected dangers.

       Some areas with extremely strong currents are  19 limits when it comes to swimming. Do your research so you know 20  not to swim, and pay attention to any warning signs posted in the area.