《烷烃》PPT课件

第3节碳氢化合物第1节烷烃，2，3，1碳氢化合物概述1。概念：仅由两种元素组成的化合物。2.分类(请在下面的方框图中填写相应的内容):链烃、环烃、烷烃、烯烃、炔烃、脂环烃、芳烃、碳、氢、4，3。几种常见碳氢化合物的比较。5，4。烃类物质的一般物理性质：(1)颜色：所有_ _ _颜色物质。(2)溶解性：两者都溶于水，同时溶于有机溶剂，如苯和乙醚。(3)密度：随着碳原子数的增加，密度逐渐增加，但高于水的密度。(4)状态：含_ _ _ _ _个碳原子的开链脂肪烃，室温下为气态。(5)沸点：随着碳原子数的增加，沸点逐渐升高。不，困难，增加，小，1 4，增加，容易。烷烃的化学性质在常温下非常不活泼，不能与_ _ _ _ _、_ _ _ _、_ _ _ _、还原剂等反应。只有在特殊条件下才能发生下列化学反应。氧化反应。(1)不与酸性高锰酸钾溶液反应，溶液颜色_ _ _ _ _。(2)燃烧反应：烷烃燃烧的通式为_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _。强酸、强碱、强氧化剂、不变。7，(2)取代反应。反应物：烷烃和卤素。反应条件：光照。(3)反应方程式：(以乙烷与Cl2反应生成氯乙烷为例)_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _。ch3c H3 cl2ch 3ch2ch 2ch 2cl HCl，8，1。区分下列陈述的正确和错误：(1)分子式符合CnH2n的烃必须是烯烃。()(2)烷烃在常温下都是气体，容易燃烧。()(3)烷烃在一定条件下可以被卤素取代。()(4)烷烃在充足的氧气中燃烧。除了二氧化碳和水，还会产生大量其他含碳化合物。()，9、【答案分析】(1)。分析：不一定。因为具有符合CnH2n的通式的烃可以是烯烃和环烷烃。(2 ).分析：常温下只有1 4个碳原子的碳氢化合物是气体，但所有的烷烃都容易燃烧，完全燃烧的产物只有水和二氧化碳。(3).分析：烷烃和卤素在光照条件下都能发生取代反应。.分析：由于烷烃只含有碳和氢两种元素，烷烃在充足的氧气中完全燃烧的唯一产物是二氧化碳和水。下列陈述是正确的()a .含有双键的物质是烯烃b .能使溴水变色的物质是烯烃c .分子式为C4H8的链烃必须是烯烃d .分子中所有原子在同一平面的烃是烯烃c .分子式为C4H8的链烃含有碳-碳双键，所以它必须是烯烃。在下列化学性质中，烷烃不具备()a .它们不能使溴水变色b .它们能在空气中燃烧c .它们能与Cl2发生取代反应d .它们能使酸性高锰酸钾溶液变色d .烷烃分子不含不饱和碳-碳双键或三键，因此酸性高锰酸钾溶液不能变色。在下面对烷烃的描述中，错误的一个是()a。在烷烃分子中，所有的化学键都是单键b。除了甲烷，许多烷烃可以淡化酸性高锰酸钾溶液的紫色。具有一般分子式CnH2n 2的烃必须是烷烃d。所有的烷烃都可以在光照条件下与氯发生取代反应，13。解析选择b .烷烃分子中的所有碳原子通过碳-碳单键连接成链，碳原子的剩余价键都与氢原子结合达到饱和。碳-碳键和碳-氢键都是单键。选项A是正确的。烷烃属于饱和链烃，它们的化学性质通常相对稳定。通常，烷烃不会与酸、碱和氧化剂(如酸性高锰酸钾溶液)反应。选项B不正确。由于分子通式CnH2n 2中的氢原子已经达到完全饱和，符合通式CnH2n 2的有机物必须是烷烃，选项c是正确的。烷烃在光照下可以被氯取代，这是铝的主要特征反应之一虽然甲烷和氯以等量混合，但事实上，反应并没有在取代生成CH3Cl的第一步停止，而是四步取代反应几乎同时发生，因此产物是CH3Cl、CH2Cl2、CH2Cl 3、CCl4和HCl。当下列等质量的碳氢化合物在相同的温度和压力下在氧气中完全燃烧时，氧气消耗的顺序是(a)乙炔、乙烯、甲烷、乙烷(b)乙烯、乙烷、甲烷、乙炔(c)甲烷、乙烯、乙炔、乙烷(d)甲烷、乙烷、乙烯、乙炔、乙炔、让碳氢化合物的分子式为CxHy。碳氢化合物在氧气中完全反应生成二氧化碳和H2O。从碳氧比和氢氧比可以看出，氢的质量分数越高，耗氧量越大。因此，当质量相等时，将CxHy转换成CHy/x形式可以快速比较耗氧量，即耗氧量越大，耗氧量越多。CH4CH4，C2H4CH2，C2H6CH3，C2H2CH，所以D是正确的。18，7。已知几种烷烃的沸点数据：据此，可以判断丙烷的沸点可能是(a)高于-0.5 b .大约-90 c .低于-88.6 d .高于-88.6。19，解析 d .烷烃的沸点随着碳原子数的增加而增加。丙烷的沸点应该在乙烷和丁烷的沸点之间。(1)看看参与反应的物质类型：如果物质类型是无机的，它们一定是取代反应，如果物质类型是有机的，它们一定不是取代反应。(2)查看产品中是否有元素形成：如果产品中有元素形成，则一定不是取代反应。(3)看是否是氧化还原反应：如果不是氧化还原反应，就不能是置换反应。(1)甲烷能与氯水反应使氯水变色吗？提示：不。甲烷只能在光照条件下被氯取代，甲烷不能淡化氯水。(2)在光照条件下，乙烷与氯反应生成1摩尔六氯乙烷需要多少摩尔氯？提示：6摩尔。取代烷烃分子中的氢原子需要一个氯分子，1摩尔六氯乙烷含有6摩尔氯原子，因此生成1摩尔六氯乙烷需要6摩尔氯。一个课外活动小组使用下图所示的装置探索了甲烷和氯气之间的反应。根据问题，回答以下问题：(CH4与Cl2反应的条件是_ _ _ _ _ _ _ _ _；如果使用阳光直射，可能会导致_ _ _ _ _ _。(2)实验中可以观察到的实验现象是：量筒内壁出现油滴，饱和盐水中沉淀出少量固体，_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _等。(3)写出甲烷和氯气生成一氯化碳的化学反应方程式，属于_ _ _ _ _ _反应(填充反应型)。(4)用饱和盐水代替水的原因是_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _。(5)实验中产生的油状液滴中的氯仿可用作局部麻醉剂。由于储存不当，它经常被空气氧化，产生高毒性气体光气。反应的化学方程式为二氯甲烷二氯甲烷氯化氢。为了防止事故，可以用来检查氯仿是否变质的试剂是_ _ _ _ _ _。a .氢氧化钠溶液b .硝酸银溶液c .稀盐酸d .水e .湿蓝石蕊试纸f .湿无色酚酞试纸。(2)有机化合物分子中的氯原子通常不能自行电离氯离子。(1)甲烷和氯气的反应需要在漫射光的作用下进行。强烈的反应可能会导致阳光直射。(2) CH3Cl、CH2Cl2、CH2Cl 3、CCl4、HCl和其它物质由2)CH4和Cl2的光照反应产生。随着反应的进行，Cl2不断被消耗，黄绿色逐渐消失。此外，生成的二氯甲烷、三氯甲烷和四氯化碳在常温下为无色液体，二氯甲烷易溶于有机溶剂，因此在量筒内壁上有油滴。由于产生的盐酸易溶于水，量筒内的压力降低，量筒内的液位上升。盐酸溶于水后，溶液中氯离子浓度增加，氯化钠固体沉淀。(3)甲烷和氯气的化学反应方程式(4) The concentration of Cl- in saturated salt water is high, which can inhibit the reaction between chlorine and water and reduce the solubility of Cl2 in water. (5) HCl is generated after chloroform metamorphism, and the product HCl can be tested. After a little liquid to be tested is added into silver nitrate solution, if precipitation is generated, chloroform metamorphism occurs; HCl dissolved in water is hydrochloric acid, which can turn wet blue litmus paper red. (1) diffuse illumination (or bright place) explosion (2) yellow-green gas color in measuring cylinder becomes lighter (3) liquid level in measuring cylinder rises (3)CH4 Cl2CH3Cl HCl substitution (4) reduces the solubility of Cl2 in water and inhibits the reaction between Cl2 and water (5)B, E,31,2.(2014 taian high school 2 test) under standard conditions, 22.4LCH4 and chlorine undergo substitution reaction under illumination. After the reaction is complete, the measured amounts of the four organic substitutes are equal, and the consumed chlorine gas is () a.0.5 mole b.2 mole c.2.5 mole d.4 mol, 32. problem solving inquiry (1) what is the relationship between the four substituted products of methane and the amount of methane? It is suggested that according to the conservation of carbon atoms, it can be judged that the total mass of the four organic substituted products of methane is the mass of methane. (2) When two chlorine atoms in chlorine gas undergo substitution reaction, do they all enter the substitution product? Hint: no. When the substitution reaction occurs, only one of the two chlorine atoms in the chlorine molecule replaces the hydrogen atom in methane, and the other chlorine atom combines with the hydrogen atom to generate HCl. In fact, it is very difficult to find a way out of this situation. 1 mole of ch4 reacts with chlorine to generate 0.25mol of CH3Cl, CH2Cl2, CHCl3 and CCl4 respectively. n(Cl)=0.25mol(1 2 3 4)=2.5mol in the four substitutes. according to the characteristics of the substitution reaction, chlorine participating in the reaction is n(Cl2)=2.5mol. If the saturated sodium chloride solution is replaced by the saturated sodium silicate solution in question 1, what will be the experimental phenomenon? Note: The generated hydrogen chloride is dissolved in water to obtain hydrochloric acid, which can react with sodium silicate solution to form white colloidal precipitate. (2) Is the reaction in question 1(5) a substitution reaction? It is suggested that 2ccl3o2 2ccl2hcl does not conform to the characteristics of substitution reaction, instead of substitution reaction, it should be redox reaction. (2014 Zhoushan Senior High School Test) Under light conditions, methane and Cl2 with the same amount of substances are fully reacted, and the substance with the largest amount of products is () A.CH3ClB.CH2Cl2C.CCl4D.HCl Analytical Option D. When CH4 and Cl2 react under illumination conditions, 1 mol 1molCH3Cl and 1 mol of HCl are obtained at the same time, and 1 mol of 2Cl2 and 2 mol of HCl are obtained at the same time. It can be seen that the amount of HCl obtained in the product is the largest. , 36,2.(2014 Xiamen Senior 2 Test) As shown in the figure, the closed U-shaped tube has a section of CH4 and Cl2 mixed gas at one end, a section of gas column at the horizontal part, and the other two sections are liquid columns. It is known that liquid does not react with gas, causing CH4 and Cl2 to react slowly in slightly darker light. How does the length of the intermediate gas column change (assuming that the intermediate gas column does not move out of the horizontal part of the U-shaped tube) () A. becomes larger B. becomes smaller C. remains unchanged D. It is difficult to determine, 37. Analysis Select A. CH4 and Cl2 undergo substitution reaction under illumination conditions, and the total volume of gas decreases. The liquid level on the right decreases, the height difference between the left and right liquid columns decreases, the pressure of the intermediate gas decreases, and the volume expands. (1) The general formula of hydrocarbon combustion: CxHy (x )O2xCO2 H2O(1) When the temperature is higher than 100, the products are all gases, and the volume change of gases is V=V before -V after=1-, divided into three situations: When y=4, V=0, and the volume of gases before and after the reaction is unchanged; (2) when y0, the gas volume decreases; (3) when y4, V0, gas volume increases. , 39, V=0 is generally called the hydrogen 4 rule, that is, hydrocarbon molecules with 4 hydrogen atoms in the molecule completely burn when the temperature is higher than 100, and the volume of gas before and after the reaction is unchanged, such as CH4, C2H4, C3H4, etc. regardless of the number of carbon atoms. On the other hand, the molecular composition of hydrocarbons can also be judged according to the constant volume before and after combustion. (2) when the temperature is lower than 10(