探究溴水的颜色变化 论文

探究溴水的颜色变化 论文 探究溴水的颜色变化 汕头一中研究性学习小组 指导老师: 徐丽芹 研究小组成员;李媛媛 黄立信 邱婉榕 陈奕君 李欣祁 苏佳耀 余泽龙 庄馥菁 中文摘要:本实验利用实验法和文献资料研究法，通过对不同浓度下溴水的颜色以及溴水与某些有机溶剂、无机溶剂反应进行探究，采用控制变量法，即在研究不同浓度下溴水颜色变化时控制其它因素不变，分别按1-10倍用蒸馏水稀释液溴，观察不同浓度下溴水的颜色变化;在研究溴水溶于某些有机溶剂和无机溶剂里颜色的变化时，则控制溴水的浓度不变以及溴水与所滴加溶剂的体积相等。通过实验，有助于我们加深对溴水的了解，提高动手能力，培养创新精神，全面提升自己的综合能力。 关键词:溴水 颜色 溴水是溴单质与水的混合物。溴单质可溶于水，80%以上的溴会与水反应生成氢溴酸与次溴酸，但仍然会有少量溴单质溶解在水中，所以溴水呈橙黄色。溴水在水中的溶解度不大，易溶于有机溶剂。然而对于溴水的颜色，历年来不同给出了不同的定义，准确而言，溴水究竟是什么颜色, 溴水在某些溶剂中会出现褪色现象。高中阶段通常利用溴水该性质来鉴别溶剂。那么溴水会与哪些溶液发生反应,哪些溶液又能使溴水褪色,这些引起我们的探究兴趣。 一、探究溴水的颜色变化 (一)探究不同浓度下溴水的颜色 1 和方法 1.1 实验设备: 量筒.试管10支.玻璃棒.胶头滴管 实验药品: 液溴.蒸馏水 地点: 二楼化学实验室 1.2 实验方法与步骤; 1.2.1 稀释 分别按1-10倍用蒸馏水稀释液溴。 1.2.2 观察 lujianhua (South area ahead Office Director and to war victory)]. County Government operates 3 Civil Affairs, finance, education and Finance Committee, with espionage, sabotage, standing and political team. Soon, the tomb of the Wujiang District Committee of the Kuomintang relocated to the countryside village. Pre-war, strict tomb for seventh district, its regional range for this Taoyuan town and town of Nan Ma Street, and Tan Qiu street of rotten Brook Tang West of area, in Wujiang South border, and Zhejiang Province Tongxiang County, and Wuxing County adjacent, ancient for two province (River, and Zhejiang) three House (Suzhou, and huzhou, and jiaxing) seven County (wuxing, and return Ann, and Tongxiang, and jiaxing, and show water, and Wujiang, and earthquake Ze) of make, is located in remote, territory size Lake swing dotted, river port criss-cross, easy hidden combat, and no Highway, traffic inconvenience. Therefore, this has become the refuge of many, where Wujiang gentleman most of the refuge is not the fall of four townships, at this time of grave, there has been a monstrous prosperity, Nanxun town, even the neighboring Zhejiang Province, there are also some merchants to Yan Tao DUN Cun opened shop. Cang during the depression as a regional political center and military base in the area. In May 1938, Chairman Mao Zedong in the guerrilla war in the strategic issues of: "North zone, South of the Lake of hongze Lake area branching stream of all enemy-occupied areas and along the coastal areas, should be well organized guerrilla and in rivers, lakes and estuaries and build lasting base nearby, as one aspect of the development of the national guerrilla". 观察不同浓度下溴水的颜色变化。 1.2.3 分析 分析实验现象，为溴水的颜色下一个较为全面准确的定义。 2. 结果与分析 2.1实验记录: 试管1 2 3 4 5 6 7 8 9 10 序号 稀释0 1 2 3 4 5 6 7 8 9 倍数 溶液10 20 30 40 50 60 70 80 90 100 体积 /ml 溶液红 橙红 橙红 橙黄 橙黄 橙 橙 浅橙 黄 淡黄 颜色 2.2实验结论: 溴水的颜色决定于溴水的浓度，不同浓度下溴水的颜色不同。溴在水中的溶解度不大，浓度较大的溴水颜色趋近于红色，浓度较小则趋近于黄色 。 从实验(1)中我们可以得出溴水的浓度决定，那么有没有什么东西能使溴水褪色呢,什么条件可以使溴水褪色,这些反应的本质相同吗,这又引起我们的探究兴趣。 (二)探究溴水溶于某些有机溶剂里发生的变化 1 材料和方法 1.1实验设备;量筒，试管。 实验试剂:，CCl4溶液，苯溶液 地点: 二楼化学实验室 1.2实验方法与步骤; 1.2.1用量筒量取6mL苯,倒入试管,再量取6mL液溴,振荡静置。 用量筒量取6mL四氯化碳溶液,倒入试管,再量取6mL液溴,倒入试管。 lujianhua (South area ahead Office Director and to war victory)]. County Government operates 3 Civil Affairs, finance, education and Finance Committee, with espionage, sabotage, standing and political team. Soon, the tomb of the Wujiang District Committee of the Kuomintang relocated to the countryside village. Pre-war, strict tomb for seventh district, its regional range for this Taoyuan town and town of Nan Ma Street, and Tan Qiu street of rotten Brook Tang West of area, in Wujiang South border, and Zhejiang Province Tongxiang County, and Wuxing County adjacent, ancient for two province (River, and Zhejiang) three House (Suzhou, and huzhou, and jiaxing) seven County (wuxing, and return Ann, and Tongxiang, and jiaxing, and show water, and Wujiang, and earthquake Ze) of make, is located in remote, territory size Lake swing dotted, river port criss-cross, easy hidden combat, and no Highway, traffic inconvenience. Therefore, this has become the refuge of many, where Wujiang gentleman most of the refuge is not the fall of four townships, at this time of grave, there has been a monstrous prosperity, Nanxun town, even the neighboring Zhejiang Province, there are also some merchants to Yan Tao DUN Cun opened shop. Cang during the depression as a regional political center and military base in the area. In May 1938, Chairman Mao Zedong in the guerrilla war in the strategic issues of: "North zone, South of the Lake of hongze Lake area branching stream of all enemy-occupied areas and along the coastal areas, should be well organized guerrilla and in rivers, lakes and estuaries and build lasting base nearby, as one aspect of the development of the national guerrilla". 用量筒量取6mL乙醛,倒入试管,再量取6mL液溴,倒入试管。 1.2.2 观察 观察溴水在苯、四氯化碳溶液、乙醛的颜色变化。 1.2.3 分析 分析实验现象，得出结论。 2. 结果与分析 2.1实验记录: 2.1.1苯加入溴水,液溴由黄色褪为浅黄色,有色层在上。 2.1.2溴由水中进入四氯化碳层。四氯化碳不溶于水，密度大于水，在下层，苯溶于溴为橙红色。充分萃取后上层溴水层(实际变成水)几乎无色。 lujianhua (South area ahead Office Director and to war victory)]. County Government operates 3 Civil Affairs, finance, education and Finance Committee, with espionage, sabotage, standing and political team. Soon, the tomb of the Wujiang District Committee of the Kuomintang relocated to the countryside village. Pre-war, strict tomb for seventh district, its regional range for this Taoyuan town and town of Nan Ma Street, and Tan Qiu street of rotten Brook Tang West of area, in Wujiang South border, and Zhejiang Province Tongxiang County, and Wuxing County adjacent, ancient for two province (River, and Zhejiang) three House (Suzhou, and huzhou, and jiaxing) seven County (wuxing, and return Ann, and Tongxiang, and jiaxing, and show water, and Wujiang, and earthquake Ze) of make, is located in remote, territory size Lake swing dotted, river port criss-cross, easy hidden combat, and no Highway, traffic inconvenience. Therefore, this has become the refuge of many, where Wujiang gentleman most of the refuge is not the fall of four townships, at this time of grave, there has been a monstrous prosperity, Nanxun town, even the neighboring Zhejiang Province, there are also some merchants to Yan Tao DUN Cun opened shop. Cang during the depression as a regional political center and military base in the area. In May 1938, Chairman Mao Zedong in the guerrilla war in the strategic issues of: "North zone, South of the Lake of hongze Lake area branching stream of all enemy-occupied areas and along the coastal areas, should be well organized guerrilla and in rivers, lakes and estuaries and build lasting base nearby, as one aspect of the development of the national guerrilla". 2.1.3乙醛加入溴水，试液由黄色变为无色透明，未出现分层现象。 2.2实验结论: 当往溴水溶液中加入苯时,溶液分层,有色层在上;往溴水中加入四氯化碳时溶液分层,有色层在下。乙醛加入溴水溶液褪色，但未出现分层。 事实上，苯和四氯化碳通过萃取作用使溴水中的溴进入非极性有机溶剂而被萃取, 属于物理变化;而溴水与乙醛发生反应使溶液变色,说明溴水与还原性强的含醛基的物质发生氧化还原反应,使溴水褪色。属于化学变化。 (三)研究溴水溶于某些无机溶剂里颜色的变化 1 材料和方法 1.1实验设备: 量筒.试管.胶头滴管 实验药品: 溴水.NaOH溶液. Na2CO3溶液. AgNO3溶液 地点:二楼化学实验室 1.2实验方法与步骤; 1.2.1用量筒量取2mL溴水,倒入试管中,再用量筒量取2mL氢氧化钠溶液,倒入试管 用量筒量取2mL溴水,倒入试管,再用量筒量取2mL碳酸钠溶液,倒入试管 用量筒量取2mL溴水,再用量筒量取2mL硝酸银溶液,倒入试管 1.2.2 观察 lujianhua (South area ahead Office Director and to war victory)]. County Government operates 3 Civil Affairs, finance, education and Finance Committee, with espionage, sabotage, standing and political team. Soon, the tomb of the Wujiang District Committee of the Kuomintang relocated to the countryside village. Pre-war, strict tomb for seventh district, its regional range for this Taoyuan town and town of Nan Ma Street, and Tan Qiu street of rotten Brook Tang West of area, in Wujiang South border, and Zhejiang Province Tongxiang County, and Wuxing County adjacent, ancient for two province (River, and Zhejiang) three House (Suzhou, and huzhou, and jiaxing) seven County (wuxing, and return Ann, and Tongxiang, and jiaxing, and show water, and Wujiang, and earthquake Ze) of make, is located in remote, territory size Lake swing dotted, river port criss-cross, easy hidden combat, and no Highway, traffic inconvenience. Therefore, this has become the refuge of many, where Wujiang gentleman most of the refuge is not the fall of four townships, at this time of grave, there has been a monstrous prosperity, Nanxun town, even the neighboring Zhejiang Province, there are also some merchants to Yan Tao DUN Cun opened shop. Cang during the depression as a regional political center and military base in the area. In May 1938, Chairman Mao Zedong in the guerrilla war in the strategic issues of: "North zone, South of the Lake of hongze Lake area branching stream of all enemy-occupied areas and along the coastal areas, should be well organized guerrilla and in rivers, lakes and estuaries and build lasting base nearby, as one aspect of the development of the national guerrilla". 观察溴水在氢氧化钠、碳酸钠、硝酸银的颜色变化。 1.2.3 分析 分析实验现象，得出结论。 2. 结果与分析 2.1实验记录: 2.1.1 溶液先由淡黄色变为无色透明.未出现分层现象 2.1.2 溶液由黄色变为无色透明,未出现分层现象,生成能使澄清石灰水变浑浊的气体 2.1.3 溶液由黄色变为无色透明,未出现分层现象。 2.2实验结论: 溴的化学性质比较活泼，能与许多物质因反应而褪色。 溴和氢氧化钠;Br2 + 2NaOH ===== NaBr + NaBrO + H2O 溴和碳酸钠:Br2 + 2NaHCO3 ===== NaBr + NaBrO + 2CO2 + H2O 溴和硝酸银:Br2 + 2AgNO3 + H2O ==== AgBr ?+ 2HNO3 因此，通过这几次实验，综合我们查阅的资料，我们出使溴水化学褪色的条件; (1)、遇强碱溶液褪色 如:向溴水中加入NaOH溶液，溴水的橙色褪 去。 lujianhua (South area ahead Office Director and to war victory)]. County Government operates 3 Civil Affairs, finance, education and Finance Committee, with espionage, sabotage, standing and political team. Soon, the tomb of the Wujiang District Committee of the Kuomintang relocated to the countryside village. Pre-war, strict tomb for seventh district, its regional range for this Taoyuan town and town of Nan Ma Street, and Tan Qiu street of rotten Brook Tang West of area, in Wujiang South border, and Zhejiang Province Tongxiang County, and Wuxing County adjacent, ancient for two province (River, and Zhejiang) three House (Suzhou, and huzhou, and jiaxing) seven County (wuxing, and return Ann, and Tongxiang, and jiaxing, and show water, and Wujiang, and earthquake Ze) of make, is located in remote, territory size Lake swing dotted, river port criss-cross, easy hidden combat, and no Highway, traffic inconvenience. Therefore, this has become the refuge of many, where Wujiang gentleman most of the refuge is not the fall of four townships, at this time of grave, there has been a monstrous prosperity, Nanxun town, even the neighboring Zhejiang Province, there are also some merchants to Yan Tao DUN Cun opened shop. Cang during the depression as a regional political center and military base in the area. In May 1938, Chairman Mao Zedong in the guerrilla war in the strategic issues of: "North zone, South of the Lake of hongze Lake area branching stream of all enemy-occupied areas and along the coastal areas, should be well organized guerrilla and in rivers, lakes and estuaries and build lasting base nearby, as one aspect of the development of the national guerrilla". Br2 + 2NaOH =NaBr + NaBrO + H2O (2)、遇某些盐溶液褪色 如:向溴水中加入碳酸钠或硝酸银溶液可使 溴水的橙色褪色 (3)、遇某些还原剂褪色 溴水中的溴具有较强的氧化性，遇某些还原 剂会因氧化还原反应而使溴水的橙色褪去。如;溴水与乙醛发生氧化还原反 应使乙醛褪色。 (4)与不饱和的化合物的加成褪色 例如，CH2=CH2+Br2=CH2BrCH2Br CH2=CH-COOH+Br2=CH2BrCHBrCOOH (5)与有机化合物的取代褪色 另外，溴水还可与酸性高锰酸钾溶液一起检验苯的同系物，即苯 的同系物可使酸性高锰酸钾溶液褪色，也能使溴水褪色，而苯不能使 酸性高锰酸钾溶液褪色也不能使溴水褪色 二、实验结论 溴水的颜色决定于溴水的浓度，不同浓度下溴水的颜色不同。溴在水中的溶解度不大，浓度较大的溴水颜色趋近于红色，浓度较小则趋近于黄色 。 溴的化学性质比较活泼，能与许多物质因反应而褪色。 苯和四氯化碳通过萃取作用使溴水中的溴进入非极性有机溶剂而被萃取, 属于物理变化;而溴水与乙醛发生反应使溶液变色,说明溴水与还原性强的含醛基的物质发生氧化还原反应,使溴水褪色。属于化学变化。 溴水遇强碱溶液可以褪色。如:向溴水中加入NaOH溶液，溴水的橙色褪去。 Br2 + 2NaOH =NaBr + NaBrO + H2O 溴水遇某些盐溶液可以褪色。如:向溴水中加入碳酸钠或硝酸银溶液可使溴水的橙色褪色 溴水遇某些还原剂可以褪色。溴水中的溴具有较强的氧化性，遇某些还原剂会因氧化还原反应而使溴水的橙色褪去。如;溴水与乙醛发生氧化还原反应使乙醛褪色。 溴水与不饱和的化合物的加成褪色。例如，CH2=CH2+Br2=CH2BrCH2Br lujianhua (South area ahead Office Director and to war victory)]. County Government operates 3 Civil Affairs, finance, education and Finance Committee, with espionage, sabotage, standing and political team. Soon, the tomb of the Wujiang District Committee of the Kuomintang relocated to the countryside village. Pre-war, strict tomb for seventh district, its regional range for this Taoyuan town and town of Nan Ma Street, and Tan Qiu street of rotten Brook Tang West of area, in Wujiang South border, and Zhejiang Province Tongxiang County, and Wuxing County adjacent, ancient for two province (River, and Zhejiang) three House (Suzhou, and huzhou, and jiaxing) seven County (wuxing, and return Ann, and Tongxiang, and jiaxing, and show water, and Wujiang, and earthquake Ze) of make, is located in remote, territory size Lake swing dotted, river port criss-cross, easy hidden combat, and no Highway, traffic inconvenience. Therefore, this has become the refuge of many, where Wujiang gentleman most of the refuge is not the fall of four townships, at this time of grave, there has been a monstrous prosperity, Nanxun town, even the neighboring Zhejiang Province, there are also some merchants to Yan Tao DUN Cun opened shop. Cang during the depression as a regional political center and military base in the area. In May 1938, Chairman Mao Zedong in the guerrilla war in the strategic issues of: "North zone, South of the Lake of hongze Lake area branching stream of all enemy-occupied areas and along the coastal areas, should be well organized guerrilla and in rivers, lakes and estuaries and build lasting base nearby, as one aspect of the development of the national guerrilla". CH2=CH-COOH+Br2=CH2BrCHBrCOOH 溴水与有机化合物的取代褪色。 另外，溴水还可与酸性高锰酸钾溶液一起检验苯的同系物，即苯的同系物可使酸性高锰酸钾溶液褪色，也能使溴水褪色，而苯不能使酸性高锰酸钾溶液褪色也不能使溴水褪色。 三、交流 由于我们第一次实验，因此实验中的困难常令我们束手无策;还有实验 室化学试剂不足的缘故，实验结果并不能达到预期的目的。但通过这次实验 我们掌握了课本中学不到的实践技能，提高了动手能力，总体而言我从这次 课题研究得到很大收获。 ——庄馥菁 由于这次实验得不到较纯的溴水，导致了实验的结果出现误差，不过每 次实验都还是较为顺利地完成了，大家都很开心地在一起认真探究，对溴水 也有了更多的认识，老师也在一旁指导我们操作，通过这次课题研究，增强 了同学间的交流互动。 ——李媛媛 虽然这次实验不是很成功，但是关于溴水的性质还是有所了解了，在实 验过程中，也培养了我们动手的能力——陈奕君 在实验中不可避免地有一些不恰当的操作需要老师同学们的纠正，在此 感谢提供了研究资料的同学和指导老师。 最后，我们向徐老师表示真诚的谢意。 四、参考文献 《高中化学选修五》——有机化学基础 lujianhua (South area ahead Office Director and to war victory)]. County Government operates 3 Civil Affairs, finance, education and Finance Committee, with espionage, sabotage, standing and political team. Soon, the tomb of the Wujiang District Committee of the Kuomintang relocated to the countryside village. Pre-war, strict tomb for seventh district, its regional range for this Taoyuan town and town of Nan Ma Street, and Tan Qiu street of rotten Brook Tang West of area, in Wujiang South border, and Zhejiang Province Tongxiang County, and Wuxing County adjacent, ancient for two province (River, and Zhejiang) three House (Suzhou, and huzhou, and jiaxing) seven County (wuxing, and return Ann, and Tongxiang, and jiaxing, and show water, and Wujiang, and earthquake Ze) of make, is located in remote, territory size Lake swing dotted, river port criss-cross, easy hidden combat, and no Highway, traffic inconvenience. Therefore, this has become the refuge of many, where Wujiang gentleman most of the refuge is not the fall of four townships, at this time of grave, there has been a monstrous prosperity, Nanxun town, even the neighboring Zhejiang Province, there are also some merchants to Yan Tao DUN Cun opened shop. Cang during the depression as a regional political center and military base in the area. In May 1938, Chairman Mao Zedong in the guerrilla war in the strategic issues of: "North zone, South of the Lake of hongze Lake area branching stream of all enemy-occupied areas and along the coastal areas, should be well organized guerrilla and in rivers, lakes and estuaries and build lasting base nearby, as one aspect of the development of the national guerrilla". lujianhua (South area ahead Office Director and to war victory)]. County Government operates 3 Civil Affairs, finance, education and Finance Committee, with espionage, sabotage, standing and political team. Soon, the tomb of the Wujiang District Committee of the Kuomintang relocated to the countryside village. Pre-war, strict tomb for seventh district, its regional range for this Taoyuan town and town of Nan Ma Street, and Tan Qiu street of rotten Brook Tang West of area, in Wujiang South border, and Zhejiang Province Tongxiang County, and Wuxing County adjacent, ancient for two province (River, and Zhejiang) three House (Suzhou, and huzhou, and jiaxing) seven County (wuxing, and return Ann, and Tongxiang, and jiaxing, and show water, and Wujiang, and earthquake Ze) of make, is located in remote, territory size Lake swing dotted, river port criss-cross, easy hidden combat, and no Highway, traffic inconvenience. Therefore, this has become the refuge of many, where Wujiang gentleman most of the refuge is not the fall of four townships, at this time of grave, there has been a monstrous prosperity, Nanxun town, even the neighboring Zhejiang Province, there are also some merchants to Yan Tao DUN Cun opened shop. Cang during the depression as a regional political center and military base in the area. In May 1938, Chairman Mao Zedong in the guerrilla war in the strategic issues of: "North zone, South of the Lake of hongze Lake area branching stream of all enemy-occupied areas and along the coastal areas, should be well organized guerrilla and in rivers, lakes and estuaries and build lasting base nearby, as one aspect of the development of the national guerrilla".