您所在的当前位置：高中化学试题 >

氧化剂和还原剂

> 工业制造金刚砂(SiC)的化学方程式如下：SiO 2＋3C===SiC＋2CO↑.在这个氧化还原反应中，氧化剂和还原剂的物质的量之比是 [ ] A．3∶5 B．1∶2 C．2∶1 D．1∶1

问题：

发布时间：2024-09-09

工业制造金刚砂(SiC)的化学方程式如下：SiO ₂＋3C===SiC＋2CO↑.在这个氧化还原反应中，氧化剂和还原剂的物质的量之比是
[     ]
A．3∶5
B．1∶2
C．2∶1
D．1∶1

参考答案：

提问用户：pl***Jv3

可能感兴趣的题目：

1 We"ve asked the neighbours to the house for us while we"re away. [ ] A. have an eye for B. keep an eye on C. keep an eye open D. keep eye on
2 从某一时刻的遥感影像图中，不能获取的信息是 [ ] A、森林火灾面积 B、土地干旱程度 C、洪峰流量 D、植物病虫害程度
3 下列化学方程式中，书写正确的是 A.3Fe+2O2═Fe3O4 B.2Fe+6HCl═2FeCl3+3H2↑ C.Na2CO3+2HCl═2NaCl+H2O+CO2↑ D.CuSO4+NaOH═CuOH↓+NaSO4
4 He never chats with others. He always _________ everything to himself. A.keeps B.lets C.makes D.speaks
5 People don"t now believe in the _____ of ghosts. [ ] A. birth B. evidence C. existence D. occurrence
6 挤牛奶的女工常与患牛痘的牛接触，她们的手上会出现牛痘的脓疱，但在天花流行时，却不感染天花。这种免疫力的产生与下列哪种细胞器的关系最密切？ [ ] A．线粒体 B．中心体 C．溶酶体 D．核糖体
7 消费者对既定商品的需求，不仅受该商品价格变动的影响，而且受相关商品价格变动的影响。如果A商品和B商品的关系如下表，则表中①②分别表明A、B两种商品之间的关系是 [ ] A．互为替代品、互补商品 B．互补商品、互为替代品 C．生活必需品、高档耐用品 D．高档耐用品、生活必需品
8 Pandas are a little shy A.very B.a lot C.lots of D.kind of
9 下列各组溶液，不另加其他试剂就可以将它们分别开的是C A．NaCl, HCl, NaAlO2, NaHCO3 B．Na2SO4, KNO3,(NH4)2SO4,MgCl2 C．FeCl3, NaOH, AlCl3, HNO3 D．AgNO3, NaCl, Na2SO4, NaI
10 D Providing small classes for at least several grades starting in early primary school gives students the best chance to succeed in late grades, according to groundbreaking new research from a Michigan State University scholar. The research by Spyros Konstantopoulos, a professor of education, is the first to examine the effects of class size over a period and for all levels of students. The study appears in the American Journal of Education. He is also a member of a group for the Department of Education’s Instiute of Education Sciences that will give official advice on class size to the states. He said the advice will mirror his research: the best plan is to provide continuous small classes(13 to 17 students) for at least several years starting in kindergarten or first grade. “For a logn time states thought they could just do it in kindergarten or first grade for one year and get the benefits,” He said. “I don’t believe that. I think you need at least a few years in a row where all students, and especially low-achievers, receive the treatment, and then you see the benefits later.” His research used data from the Project Star study in Tennessee that analyzed the effects of class size on more than 11,000 students in primary and middle school. He found that students who had been in small classes from kindergarten through third grade had actually higher test scores in grades four through eight than students who been in larger classes early on. Students from all achievement levels benefited from small classes, the research found. “But low-achievers benefited the most, which narrowed the achievement gap with high –achievers in science, reading and math, ” he said. Although the study didn’t consider classroom practices, he said the reason for the narrowing gap is likely due to low-achieving students receiving more attention from teachers. “This is especially important in poorer schools because teacher effectiveness matters more in schools with more disadvantaged and low-performing students, ” he said. 48．The professor argues about ________ . A．the size of the class B．the period of the class C．the attention from teachers D．the achievements of students 49．The result of the research shows that _________. A．small classes for one year in early grade are enough B．continuous small classes help students achieve more C．it’s best to attend small classes in kindergarten D．small classes do equal good to students of all levels 50．What can we infer from the passage? A．High achievers will not benefit from small classes. B．Continuous small classes have not been widely accepted. C．Low-achievers should be separated from high-achievers. D．Teachers’ attention matters less than classroom practices. 51．The underlined word “This” in the last paragraph refers to _______. A．the gap between low and high achievers B．continuous small classes C．classroom practices in later grades D．the Project Star Sturdy