题干

将一定质量的铁、氧化铁、氧化铜的混合物粉末放入100mL 4.40mol/L盐酸中,充分反应后产生896mL H2(标准状况),残留固体1.28g.过滤,滤液中无Cu2+.将滤液加水稀释到200mL,测得其中c(H+)为0.400mol/L.则原混合物中单质铁的质量是(   )

A:2.24g

B:3.36g

C:5.60g

D:10.08g

上一题 下一题 0.0难度 选择题 更新时间:2020-03-28 06:49:19

答案(点此获取答案解析)

C

同类题2

阅读下列材料:
材料一 在我国早期封建化城市形成的过程中,真正起关键作用的是统治阶级的政治、军事需要。早期建筑的原因不外乎有以下三种:第一,大小诸侯国国都都是政治中心,都需要筑城;第二,各国纷争中需要在战略要地筑城;第三,在交通要道和人口密集的地方,封建社会的城市商业逐渐繁荣起来……
——胡如雷《中国封建社会形态研究》
材料二  工业革命将数以千计的人带到拥挤的城市与乡镇找工作。如英国的曼彻斯特在1780年建立起第一个大型机械化的棉纺织厂,不久便成为一个主要的纺织中心,人口由1750年的18000人增加到1851年人口普查时的30万人,大多数人口属于工人阶级和移民。城市化进程的加快,超过了城市资源和环境的承载力,严重影响了城市的可持续发展。
——何成刚《史料教学中的方法与策略》
材料三 鸦片战争后,在西方工业文明冲击下,随着资本主义生产方式和中国近代工商业的发展,中国传统的封建城市开始向近代资本主义城市方向发展。19世纪70年代以后,棉纺业、面粉、造纸、印刷、航运等各类民族工业,在上海、宁波、广州、天津等城市逐步发展起来。
——马春辉《中国城市化问题论纲》
材料四   1949—2006年我国城市化人口增长率变化图

根据材料,结合所学知识,回答问题。
(1)根据材料一,归纳中国封建社会城市形成的原因。
(2)概述材料二中工业革命给城市带来的影响。
(3)材料三中,鸦片战争后中国传统的封建城市开始向近代资本主义城市方向发展的原因有哪些?
(4)观察材料四柱状图,说出我国城市人口增长最快的时间段,并简述理由
(5)综上所述,谈谈你对城市化发展进程的认识。

同类题4

阅读理解

       I prefer Lynne Truss's phraseology: I am a grammar “sticker”. And, like Truss—author of Eats, Shoots & Leaves—I have a “zero tolerance” approach to grammar mistakes that make people look stupid.

       Now, Truss and I disagree on what it means to have “zero tolerance”. She thinks that people who mix up basic grammar “deserve to be struck by lightning, hacked (砍) up on the spot and buried in an unmarked grave”, while I just think they deserve to be passed over for a job—even if they are otherwise qualified for the position.

       Everyone who applies for a position at either of my companies, iFixit or Dozuki, takes a compulsory grammar test. If job hopefuls can't distinguish between “to” and “too”, their applications go into the bin.

       Of course, we write for a living. iFixit. com is the world's largest online repair manual (指南), and Dozuki helps companies write their own technical documentation, like paperless work instructions and step­by­step user manuals. So, it makes sense that we've made a strong strike against grammar errors.

        But grammar is relevant for all companies. Yes, language is constantly changing, but that doesn't make grammar unimportant. Good grammar is credibility, especially on the Internet. And, for better or worse, people judge you if you can't tell the difference between “their” “there” and “they're”.

       Good grammar makes good business sense—and not just when it comes to hiring writers. Writing isn't in the official job description of most people in our office. Still, we give our grammar test to everybody, including our salespeople, our operations staff, and our programmers.

       Grammar signifies more than just a person's ability to remember high school English. I've found that people who make fewer mistakes on a grammar test also make fewer mistakes when they are doing something completely unrelated to writing—like stocking shelves or labeling parts. It is the same with programmers. Applicants who don't think writing is important are likely to think lots of other things also aren't important.