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1.
设计探究过氧化钠能否与氢气、碳发生氧化还原反应的实验。实验证明:过氧化钠与氢气反应生成氢氧化钠,与炭粉反应生成碳酸钠和氧化钠。  相似文献   

2.
过氧化钠与二氧化碳反应的演示实验设计   总被引:1,自引:0,他引:1  
阎娜花 《化学教育》2003,24(4):44-44
高中化学新教材第一册第三章中有“过氧化钠与水的反应的演示实验” ,学生观察实验后情绪高涨 ,但有些疑惑 ,他们一直认为水是用来灭火的 ,为什么水还能“生火”呢 ?并且好多学生问 :二氧化碳是否也可以用来“生火” ?书中只有过氧化钠与二氧化碳反应 ( 2Na2 O2 +2CO2 =2Na2 CO3 +O2 )的知识点 ,而没有相关的实验 ,为了给学生以感性认识 ,激发他们的探究意识 ,打破思维定式 ,经过多次探索和实践 ,特设计如下实验。方法一1 实验用品药匙、石棉网、长玻璃管、三角架、棉花、Na2 O2粉末2 实验装置 (三角架略 )图 13 实验步骤与现象( 1)…  相似文献   

3.
在中学教材里,过氧化钠的颜色是这样叙述的:过氧化钠是淡黄色的固体。对这一叙述,笔者认为有改进的必要: 一、过氧化钠的颜色是一个没有统一看法的问题。不同的书中,有不同的叙述。从我国已出版的书中,大体就能见以下几种: 1.纯的过氧化钠是淡黄色的固体(或粉末)[2].[3].[4].[5]. 2.纯的过氧化钠是无色粉末,工业制备的过氧化钠因含有超氧化钠(NaO_2)杂质而呈黄色[6].[7].[8].[9]。 3.叙述过氧化钠的工业制法,不叙述过氧化钠的颜色[10].[11]。 4.说过氧化钠的工业制法,并指出所得产  相似文献   

4.
李俊生  胡志刚 《化学教育》2011,32(1):69-72,80
1.问题的提出 过氧化钠与水反应的实验是中学化学课堂重点演示实验,从目前情况看该实验的研究还有许多亟待解决的问题.特别是过氧化钠与水反应生成氧气质量的理论计算和实验结果的矛盾[1]、过氧化钠与水反应后溶液具有漂白性的原因[2-3]、双线桥标出过氧化钠与水反应过程中电子的得失[4]等疑难问题更为突出,所以从实验和理论上对上述疑难问题加以认真的研究是非常必要的.  相似文献   

5.
李嘉 《化学教育》2018,39(15):76-77
针对教材中乙酸乙酯制备实验的不足,结合自身实践,使用真空采血管设计微型减压蒸馏装置用于制备乙酸乙酯。通过实验证明,该装置安全高效、实验效果好、简便易携。  相似文献   

6.
高考化学实验试题的创意与设计   总被引:4,自引:0,他引:4  
王后雄 《化学教育》2004,25(4):36-39
摘要本文通过分析近几年高考化学实验试题命题的选材及创意的特点,提出了高考化学实验试题装置、操作创新设计的基本要求,并以启普发生器反应器的设计、防止液体倒吸发生装置的设计、测量气体体积装置的设计、喷泉实验装置的设计、具有特殊作用的实验改进装置的设计、Fe(OH)2的制备操作装置的设计为例剖析了高考实验命题与解题的思路。  相似文献   

7.
从理论和实验2个方面探究了过氧化钠和氯化铵加热的反应,得出过氧化钠不能氧化氯化钠但可以氧化浓盐酸的结论,并对反应机理提出了假设。  相似文献   

8.
针对传统8-羟基喹啉制备实验装置存在的不足,在现有大学有机化学教学实验的基础上,重新设计一种8-羟基喹啉合成的实验装置,该装置利用自制的微型小漏斗和常规磨口玻璃仪器连接组装。解决了8-羟基喹啉制备实验中,后期未反应的邻硝基苯酚处理和8-羟基喹啉分离问题。实验结果表明,改进后的实验装置操作简便,安全,节省时间,实验效率明显得到了提高。  相似文献   

9.
江建 《化学教育》2010,31(1):66-67
根据教学过程中学生提出的过氧化钠能否氧化浓盐酸的问题,通过实验验证并分析了过氧化钠、过氧化氢与浓盐酸反应产生氯气并同时伴有氧气生成的情况。  相似文献   

10.
刘加虎 《化学教育》2010,31(6):85-85
在普通高中课程标准实验教科书<化学1 (必修)>(人教版)第三章第二节中[1],介绍了重要的金属化合物过氧化钠,教材中研究了过氧化钠在常温下能和水、二氧化碳发生反应,说明过氧化钠在常温下很容易与一些非金属氧化物反应,释放出氧气,表现出很强的氧化性,在对应的教师用书上还介绍过氧化钠能够把铁氧化生成高铁酸钠[2],说明过氧化钠能够氧化一些比较活泼的金属.笔者经过研究发现,过氧化钠除与比较活泼的金属铁反应外,还能和金属铜发生反应,而且在不同的反应条件下产物是完全不同的.  相似文献   

11.
Scandium magnesium gallide, Sc2MgGa2, and yttrium magnesium gallide, Y2MgGa2, were synthesized from the corresponding elements by heating under an argon atmosphere in an induction furnace. These intermetallic compounds crystallize in the tetragonal Mo2FeB2‐type structure. All three crystallographically unique atoms occupy special positions and the site symmetries of (Sc/Y, Ga) and Mg are m2m and 4/m, respectively. The coordinations around Sc/Y, Mg and Ga are pentagonal (Sc/Y), tetragonal (Mg) and triangular (Ga) prisms, with four (Mg) or three (Ga) additional capping atoms leading to the coordination numbers [10], [8+4] and [6+3], respectively. The crystal structure of Sc2MgGa2 was determined from single‐crystal diffraction intensities and the isostructural Y2MgGa2 was identified from powder diffraction data.  相似文献   

12.
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15.
The structures of the hypophosphites KH2PO2 (potassium hypophosphite), RbH2PO2 (rubidium hypophosphite) and CsH2PO2 (caesium hypophosphite) have been determined by single‐crystal X‐ray diffraction. The structures consist of layers of alkali cations and hypophosphite anions, with the latter bridging four cations within the same layer. The Rb and Cs hypophosphites are isomorphous.  相似文献   

16.
Summary The ability of [MoS4]2–, anions to be used as ligands for transition metal ions has been widely demonstrated, especially with Fe2+. The present study has been restricted to linear complexes such as (NEt4)2 [Cl2FeS2MoS2] and (NEt4)2[Cl2FeS2MoS2FeCl2]. Their electrochemical properties are described: upon electrochemical reduction, these compounds yield MoS2, as a black precipitate, and an iron complex in solution, assumed to be [SFeCl2]2–. The electrochemical reduction goes through two electron transfers, coupled with the breakdown of the molecular skeleton: a DISPl and an ECE mechanism. Depending on the solvent, the following equilibrium may be observed: [Cl4Fe2MoS4]2–[Cl2FeMoS4]2–+FeCl2. The equilibrium constant, KD, was evaluated by differential pulse polarography. KD is tightly related to the donor number of the solvent.  相似文献   

17.
On Dialkali Metal Dichalcogenides β-Na2S2, K2S2, α-Rb2S2, β-Rb2S2, K2Se2, Rb2Se2, α-K2Te2, β-K2Te2 and Rb2Te2 The first presentation of pure samples of α- and β-Rb2S2, α- and β-K2Te2, and Rb2Te2 is described. Using single crystals of K2S2 and K2Se2, received by ammonothermal synthesis, the structure of the Na2O2 type and by using single crystals of β-Na2S2 and β-K2Te2 the Li2O2 type structure will be refined. By combined investigations with temperature-dependent Guinier-, neutron diffraction-, thermal analysis, and Raman-spectroscopy the nature of the monotropic phase transition from the Na2O2 type to the Li2O2 type will be explained by means of the examples α-/β-Na2S2 and α-/β-K2Te2. A further case of dimorphic condition as well as the monotropic phase transition of α- and β-Rb2S2 is presented. The existing areas of the structure fields of the dialkali metal dichalcogenides are limited by the model of the polar covalence.  相似文献   

18.
Wu YT  Linden A  Siegel JS 《Organic letters》2005,7(20):4353-4355
[reaction: see text] Fluoranthene 2 and heptacycle 3 are easily accessible from the reaction of diyne 1 and norbornadiene (NBD) in the presence of the rhodium catalyst. The unusual [(2+2)+(2+2)] adduct 3 was confirmed by the X-ray crystal structure analysis.  相似文献   

19.
[(n‐Bu)2Sn(O2PPh2)2] ( 1 ), and [Ph2Sn(O2PPh2)2] ( 2 ) have been synthesized by the reactions of R2SnCl2 (R=n‐Bu, Ph) with HO2PPh2 in Methanol. From the reaction of Ph2SnCl2 with diphenylphosphinic acid a third product [PhClSn(O2PPh2)OMe]2 ( 3 ) could be isolated. X‐ray diffraction studies show 1 to crystallize in the monoclinic space group P21/c with a = 1303.7(1) pm, b = 2286.9(2) pm, c = 1063.1(1) pm, β = 94.383(6)°, and Z = 4. 2 crystallizes triclinic in the space group , the cell parameters being a = 1293.2(2) pm, b = 1478.5(4) pm, c = 1507.2(3) pm, α = 98.86(3)°, β = 109.63(2)°, γ = 114.88(2)°, and Z = 2. Both compounds form arrays of eight‐membered rings (SnOPO)2 linked at the tin atoms to form chains of infinite length. The dimer 3 consists of a like ring, in which the tin atoms are bridged by methoxo groups. It crystallizes triclinic in space group with a = 946.4(1) pm, b = 963.7(1) pm, c = 1174.2(1) pm, α = 82.495(6)°, β = 66.451(6)°, γ = 74.922(6)°, and Z = 1 for the dimer. The Raman spectra of 2 and 3 are given and discussed.  相似文献   

20.
The structures of isomorphous monoclinic strontium and lead bis­(di­hydrogenphosphate), Sr(H2PO2)2 and Pb(H2PO2)2, and orthorhombic barium bis­(di­hydrogen­phos­phate), Ba(H2PO2)2, consist of layers of hypophosphite anions and metal cations exhibiting square antiprismatic coordination by O atoms. The Sr and Pb atoms are located on sites with point symmetry 2, and the Ba atoms are on sites with point symmetry 222. Within the layers, each anion bridges four metal cations.  相似文献   

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